Exam 2 Statistical Analysis Part 1 of 1 - Question 1 of 20 5.0/ 100.0 Points 0.0/ 5.0 Points The stacked bar chart below shows the percentages of death due to cancer in four geographic regions of the U.S. that occurred in three ethnic groups in 2003. In which geographic area did Hispanics account for their lowest percentage of cancer deaths in 2003? A. Northeast B. Midwest C. South D. West Question 2 of 20 0.0/ 5.0 Points The table shows the price of a volatile stock from the months January 1999 through December 1999 as determined by the closing price on the last trading day of the month. The price is rounded to the nearest dollar. Which time series line chart represents the data? A. B. C. D. None of the above Question 3 of 20 0.0/ 5.0 Points The histogram below shows the ages of the actors who won the Academy Award for best actor from 1970 to 2006. How many of the award winners were 50 years old or older at the time they won their Oscar? A. 6 B. 9 C. 15 D. 18 Question 4 of 20 Which line chart below represents the data in the table? 0.0/ 5.0 Points A. B. C. D. None of the above Question 5 of 20 Identify the utility that decreases as a percentage of the total utility bill from January to June. 5.0/ 5.0 Points A. Electric B. Natural Gas C. Water D. None decrease from January to June. Question 6 of 20 0.0/ 5.0 Points The bar chart shows the relative frequencies of winners of the Wimbledon women's singles tennis title for 1976 - 1995. How many titles did Graf and Navratilova win? A. .75 B. 14 C. 15 D. 40 Question 7 of 20 0.0/ 5.0 Points The stacked bar chart below shows the percentages of death due to cancer in four geographic regions of the U.S. that occurred in three ethnic groups in 2003. In which geographic area did Hispanics account for their highest percentage of cancer deaths in 2003? A. Northeast B. Midwest C. South D. West Question 8 of 20 Identify the utility that has its smallest percentage of the total bill in March. 0.0/ 5.0 Points A. Gas B. Electric C. Water D. None of the utilities has its smallest percentage of the total bill in March Question 9 of 20 0.0/ 5.0 Points The data below are the numbers of hours of homework done as reported by 24 high school juniors for the last week in September, 2006. 6, 5, 6, 4, 6, 6, 9, 7, 6, 3, 8, 5, 5, 8, 6, 5, 8, 6, 5, 7, 5, 8, 7, 4 Using bins of 2 hours width, which relative frequency histogram represents the data? A. B. C. D. None of the above Question 10 of 20 0.0/ 5.0 Points The stem-and-leaf plot below shows the weights in pounds of halibut caught on an Alaskan fishing boat for one day. List all of the original weights. A. 29, 31, 36, 37, 38, 40, 42, 43, 46, 47, 51, 52, 54, 60 B. 29, 31, 32, 36, 37, 38, 38, 40, 42, 43, 46, 47, 51, 54, 60 C. 29, 31, 32, 36, 37, 38, 40, 42, 43, 45, 46, 47, 51, 52, 54, 60 D. 29,31,32,36,37,37,38,38,40,42,43,43,45,45,46,47,51,52,54,60 Question 11 of 20 0.0/ 5.0 Points The following multiple line graph shows the numbers of death due to cancer in four geographic regions of the U.S. that occurred in three ethnic groups in 2003. In which geographic area was the number of cancer deaths among whites the highest in 2003? A. Northeast B. Midwest C. South D. West Question 12 of 20 0.0/ 5.0 Points The stem-and-leaf diagram below shows the highest wind velocity ever recorded in 30 different U.S. cities. The velocities are given in miles per hour. The leaf unit is 1.0. How many of the maximum wind velocities are 88 miles per hour or lower? A. 2 B. 5 C. 11 D. 18 Question 13 of 20 0.0/ 5.0 Points The ages of employees of a company are summarized in the frequency table. Which line chart below represents the data? A. B. C. D. None of the above Question 14 of 20 0.0/ 5.0 Points A nurse measured the blood pressure of each person who visited her clinic. Following is a relative-frequency histogram for the systolic blood pressure readings for those people aged between 25 and 40. Use the histogram to answer the question. The blood pressure readings were rounded down to the next whole number. Given that 600 people were aged between 25 and 40, approximately how many had a systolic blood pressure reading recorded as between 120 and 149 inclusive? A. 48% B. 250 C. 288 D. 300 Question 15 of 20 0.0/ 5.0 Points A nurse measured the blood pressure of each person who visited her clinic. Following is a relative-frequency histogram for the systolic blood pressure readings for those people aged between 25 and 40. Use the histogram to answer the question. The blood pressure readings were rounded up to the next whole number. Approximately what percentage of the people aged 25-40 had a systolic blood pressure reading greater than or equal to 130? A. 15% B. 28% C. 75% D. 90% Question 16 of 20 0.0/ 5.0 Points A machine is supposed to fill juice bottles with 16 fluid ounces of juice. The manufacturer picks a sample of bottles that have been filled by the machine and determines the volume of juice in each bottle. The results are shown in the following stem-and-leaf diagram. The leaf unit is 0.1. How many bottles were sampled? A. 9 B. 10 C. 15 D. 44 Question 17 of 20 0.0/ 5.0 Points Identify the class that has had the greatest percentage increase with respect to its initial percentage over the five decades. A. Fr B. So C. Jr D. Sr Question 18 of 20 0.0/ 5.0 Points The following dot plot represents the ages of the people in a sample selected from a group of campaign volunteers. How many people were in the sample? A. 15 B. 21 C. 27 D. 28 Question 19 of 20 0.0/ 5.0 Points The table shows the end-of-the-month checking account balance of a statistics teacher for the months January 1999 through December 1999 as determined by the closing balance on the last banking day of the month. The balance is rounded to the nearest dollar. A. B. C. D. None of the above Question 20 of 20 Find the original data from the stem-and-leaf plot. 0.0/ 5.0 Points A. 11, 18, 23, 23, 27, 33, 34, 38, 39, 43, 44 B. 2, 9, 2, 2, 4, 8, 4, 4, 6, 11, 12, 7, 8, 12 C. 13, 13, 14, 21, 21, 23, 27, 31, 31, 43, 44 D. 11, 18, 21, 21, 23, 27, 31, 33, 33, 38, 39, 43, 44 Exam 4 Part 1 of 2 - 30.0/ 50.0 Points 2.5/ 2.5 Points Question 1 of 40 Suppose you pay $1.00 to roll a fair die with the understanding that you will get back $3.00 for rolling a 5 or a 2, nothing otherwise. What is your expected value? A. $1.00 B. $0.00 C. $3.00 D. $1.00 2.5/ 2.5 Points Question 2 of 40 On a multiple choice test, each question has 6 possible answers. If you make a random guess on the first question, what is the probability that you are correct? A. 1/5 B. 1/6 C. 1/4 D. 2/5 Question 3 of 40 0.0/ 2.5 Points The data set represents the income levels of the members of a country club. Estimate the probability that a randomly selected member earns at least $98,000. 112,000 126,000 90,000 133,000 94,000 112,000 98,000 82,000 147,000 182,000 86,000 105,000 140,000 94,000 126,000 119,000 98,000 154,000 78,000 119,000 A. 0.4 B. 0.6 C. 0.66 D. 0.7 0.0/ 2.5 Points Question 4 of 40 A study of 600 college students taking Statistics 101 revealed that 54 students received the grade of A. Typically 10% of the class gets an A. The difference between this group of students and the expected value is not significant at the 0.05 level. What does this mean in this case? A. The probability that the difference occurred due to chance is less than 0.05. B. The probability of getting an A is 10% and only 9% got an A in this study. The difference is less than 5% so it is not significant. C. There is not enough information to make any conclusion. D. The probability that the difference occurred due to chance is more than 0.05. 0.0/ 2.5 Points Question 5 of 40 Suppose you have an extremely unfair coin: the probability of a head is 1/5, and the probability of a tail is 4/5. If you toss the coin 40 times, how many heads do you expect to see? A. 8 B. 6 C. 5 D. 4 2.5/ 2.5 Points Question 6 of 40 Of 1308 people who came into a blood bank to give blood, 314 people had high blood pressure. Estimate the probability that the next person who comes in to give blood will have high blood pressure (to 3 decimal places). A. 0.250 B. 0.490 C. 0.240 D. 0.160 2.5/ 2.5 Points Question 7 of 40 In the first series of rolls of a die, the number of odd numbers exceeded the number of even numbers by 5. In the second series of rolls of the same die, the number of odd numbers exceeded the number of even numbers by 11. Determine which series is closer to the 50/50 ratio of odd/even expected of a fairly rolled die. A. The second series is closer because the difference between odd and even numbers is greater than the difference for the first series. B. The first series is closer because the difference between odd and even numbers is less than the difference for the second series. C. Since 1/2 > 1/5 > 1/11, the first series is closer. D. The series closer to the theoretical 50/50 cannot be determined unless the total number of rolls for both series is given. 2.5/ 2.5 Points Question 8 of 40 If you flip a coin three times, the possible outcomes are HHH, HHT, HTH, HTT, THH, THT, TTH, TTT. What is the probability that at least two heads occur consecutively? A. 1/8 B. 3/8 C. 5/8 D. 6/8 2.5/ 2.5 Points Question 9 of 40 Suppose you have an extremely unfair coin: the probability of a head is 1/3 and the probability of a tail is 2/3. If you toss the coin 72 times, how many heads do you expect to see? A. 12 B. 22 C. 24 D. 26 2.5/ 2.5 Points Question 10 of 40 A sample space consists of 46 separate events that are equally likely. What is the probability of each? A. 1/24 B. 1/46 C. 1/32 D. 1/18 Question 11 of 40 0.0/ 2.5 Points Sammy and Sally each carry a bag containing a banana, a chocolate bar, and a licorice stick. Simultaneously, they take out a single food item and consume it. The possible pairs of food items that Sally and Sammy consumed are as follows. chocolate bar - chocolate bar licorice stick - chocolate bar banana - banana chocolate bar - licorice stick licorice stick - licorice stick chocolate bar - banana banana - licorice stick licorice stick - banana banana - chocolate bar Find the probability that no chocolate bar was eaten. A. 4/9 B. 5/9 C. 7/9 D. 5/8 2.5/ 2.5 Points Question 12 of 40 A bag contains 4 red marbles, 3 blue marbles, and 7 green marbles. If a marble is randomly selected from the bag, what is the probability that it is blue? A. 2/11 B. 3/11 C. 5/14 D. 3/14 2.5/ 2.5 Points Question 13 of 40 If a person is randomly selected, find the probability that his or her birthday is not in May. Ignore leap years. There are 365 days in a year. Express your answer as a fraction. A. 335/365 B. 334/365 C. 336/365 D. 30/365 0.0/ 2.5 Points Question 14 of 40 Based on meteorological records, the probability that it will snow in a certain town on January 1st is 0.413. Find the probability that in a given year it will not snow on January 1st in that town. A. 0.345 B. 0.425 C. 0.587 D. 0.592 Question 15 of 40 If you flip a coin three times, the possible outcomes are HHH, HHT, HTH, HTT, THH, THT, TTH, TTT. What is the probability of getting at least one head? 2.5/ 2.5 Points A. 4/9 B. 5/6 C. 7/8 D. 5/8 2.5/ 2.5 Points Question 16 of 40 Suppose you have an extremely unfair die: The probability of a 6 is 3/8, and the probability of each other number is 1/8. If you toss the die 32 times, how many twos do you expect to see? A. 2 B. 4 C. 3 D. 5 0.0/ 2.5 Points Question 17 of 40 In a poll, respondents were asked whether they had ever been in a car accident. 220 respondents indicated that they had been in a car accident and 370 respondents said that they had not been in a car accident. If one of these respondents is randomly selected, what is the probability of getting someone who has been in a car accident? Round to the nearest thousandth. A. 0.384 B. 0.380 C. 0.373 D. 0.370 2.5/ 2.5 Points Question 18 of 40 If you flip a coin three times, the possible outcomes are HHH, HHT, HTH, HTT, THH, THT, TTH, TTT. What is the probability of getting at least two tails? A. 1/2 B. 2/3 C. 3/4 D. 4/9 0.0/ 2.5 Points Question 19 of 40 A committee of three people is to be formed. The three people will be selected from a list of five possible committee members. A simple random sample of three people is taken, without replacement, from the group of five people. Using the letters A, B, C, D, E to represent the five people, list the possible samples of size three and use your list to determine the probability that B is included in the sample. (Hint: There are 10 possible samples.) A. 0.6 B. 0.4 C. 0.7 D. 0.8 0.0/ 2.5 Points Question 20 of 40 Jody checked the temperature 12 times on Monday, and the last digit of the temperature was odd six times more than it was even. On Tuesday, she checked it 18 times and the last digit was odd eight times more than it was even. Determine which series is closer to the 50/50 ratio of odd/even expected of such a series of temperature checks. A. The Monday series is closer because 1/6 is closer to 1/2 than is 1/8. B. The Monday series is closer because 6/12 is closer to 0.5 than is 8/18. C. The Tuesday series is closer because the 13/18 is closer to 0.5 than is 9/12. D. The series closest to the theoretical 50/50 cannot be determined without knowing the number of odds and evens in each series. Part 2 of 2 25.0/ 50.0 Points Question 21 of 40 0.0/ 2.5 Points Which line of the three shown in the scatter diagram below fits the data best? A. A B. B C. C D. All the lines are equally good Question 22 of 40 2.5/ 2.5 Points Which point below would be an outlier if it were on the following graph? A. (25, 20) B. (5, 12) C. (7, 5) D. (5, 3) Question 23 of 40 2.5/ 2.5 Points 30% of the fifth grade students in a large school district read below grade level. The distribution of sample proportions of samples of 100 students from this population is normal with a mean of 0.30 and a standard deviation of 0.045. Suppose that you select a sample of 100 fifth grade students from this district and find that the proportion that reads below grade level in the sample is 0.36. What is the probability that a second sample would be selected with a proportion less than 0.36? A. 0.8932 B. 0.8920 C. 0.9032 D. 0.9048 Question 24 of 40 0.0/ 2.5 Points Which graph has two groups of data, correlations within each group, but no correlation among all the data? A. B. C. D. Question 25 of 40 0.0/ 2.5 Points Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. A. 0.60 B. -0.97 C. 0.10 D. -0.60 Question 26 of 40 0.0/ 2.5 Points A random sample of 30 households was selected from a particular neighborhood. The number of cars for each household is shown below. Estimate the mean number of cars per household for the population of households in this neighborhood. Give the 95% confidence interval. A. 1.14 to 1.88 B. 1.12 to 1.88 C. 1.12 to 1.98 D. 1.14 to 1.98 Question 27 of 40 0.0/ 2.5 Points Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. A. -0.9 B. 0.1 C. 0.5 D. 0.9 2.5/ 2.5 Points Question 28 of 40 Of the 6796 students in one school district, 1537 cannot read up to grade level. Among a sample of 812 of the students from this school district, 211 cannot read up to grade level. Find the sample proportion of students who cannot read up to grade level. A. 0.14 B. 0.26 C. 211 D. 0.23 Question 29 of 40 0.0/ 2.5 Points Suggest the cause of the correlation among the data. The graph shows strength of coffee (y) and number of scoops used to make 10 cups of coffee (x). Identify the probable cause of the correlation. A. The variation in the x variable is a direct cause of the variation in the y variable. B. There is no correlation between the variables. C. The correlation is due to a common underlying cause. D. The correlation between the variables is coincidental. 0.0/ 2.5 Points Question 30 of 40 A researcher wishes to estimate the mean amount of money spent per month on food by households in a certain neighborhood. She desires a margin of error of $30. Past studies suggest that a population standard deviation of $248 is reasonable. Estimate the minimum sample size needed to estimate the population mean with the stated accuracy. A. 274 B. 284 C. 264 D. 272 Question 31 of 40 0.0/ 2.5 Points Select the best fit line on the scatter diagram below. A. A B. B C. C D. All of the lines are equally good Question 32 of 40 2.5/ 2.5 Points Eleven female college students are selected at random and asked their heights. The heights (in inches) are as follows: 67, 59, 64, 69, 65, 65, 66, 64, 62, 64, 62 Estimate the mean height of all female students at this college. Round your answer to the nearest tenth of an inch if necessary. A. It is not possible to estimate the population mean from this sample data B. 64.3 inches C. 64.9 inches D. 63.7 inches Question 33 of 40 2.5/ 2.5 Points Among a random sample of 500 college students, the mean number of hours worked per week at non-college related jobs is 14.6. This mean lies 0.4 standard deviations below the mean of the sampling distribution. If a second sample of 500 students is selected, what is the probability that for the second sample, the mean number of hours worked will be less than 14.6? A. 0.5 B. 0.6179 C. 0.6554 D. 0.3446 2.5/ 2.5 Points Question 34 of 40 A researcher wishes to estimate the proportion of college students who cheat on exams. A poll of 560 college students showed that 27% of them had, or intended to, cheat on examinations. Find the 95% confidence interval. A. 0.2323 to 0.3075 B. 0.2325 to 0.3075 C. 0.2325 to 0.3185 D. 0.2323 to 0.3185 Question 35 of 40 Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram. A. -0.9 0.0/ 2.5 Points B. 0.9 C. 0.5 D. -0.5 2.5/ 2.5 Points Question 36 of 40 Monthly incomes of employees at a particular company have a mean of $5954. The distribution of sample means for samples of size 70 is normal with a mean of $5954 and a standard deviation of $259. Suppose you take a sample of size 70 employees from the company and find that their mean monthly income is $5747. How many standard deviations is the sample mean from the mean of the sampling distribution? A. 0.8 standard deviations above the mean B. 0.8 standard deviations below the mean C. 7.3 standard deviations below the mean D. 207 standard deviations below the mean Question 37 of 40 2.5/ 2.5 Points A sample of nine students is selected from among the students taking a particular exam. The nine students were asked how much time they had spent studying for the exam and the responses (in hours) were as follows: 18, 7, 10, 13, 12, 16, 5, 20, 21 Estimate the mean study time of all students taking the exam. Round your answer to the nearest tenth of an hour if necessary. A. 13 hours B. 12.2 hours C. 13.6 hours D. It is not possible to estimate the population mean from this sample data Question 38 of 40 0.0/ 2.5 Points The scatter plot and best-fit line show the relation between the price per item (y) and the availability of that item (x) in arbitrary units. The correlation coefficient is -0.95. Determine the amount of variation in pricing explained by the variation in availability. A. 5% B. 10% C. 95% D. 90% 2.5/ 2.5 Points Question 39 of 40 Sample size = 400, sample mean = 44, sample standard deviation = 16. What is the margin of error? A. 1.4 B. 1.6 C. 2.2 D. 2.6 Question 40 of 40 2.5/ 2.5 Points The graph shows a measure of fitness (y) and miles walked weekly. Identify the probable cause of the correlation. A. The correlation is coincidental. B. There is a common underlying cause of the correlation. C. There is no correlation between the variables. D. Walking is a direct cause of the fitness. Exam 8 17.5/ 50.0 Points Part 1 of 2 - 2.5/ 2.5 Points Question 1 of 40 A consumer group claims that the mean running time for a certain type of flashlight battery is not the same as the manufacturer's claims. Determine the null and alternative hypotheses for the test described. A. H0: = Manufacturer's claims Ha: < Manufacturer's claims B. H0: = Manufacturer's claims Ha: Manufacturer's claims C. H0: = Manufacturer's claims Ha: > Manufacturer's claims D. H0: Manufacturer's claims Ha: = Manufacturer's claims 0.0/ 2.5 Points Question 2 of 40 A nationwide study of American homeowners revealed that 65% have one or more lawn mowers. A lawn equipment manufacturer, located in Omaha, feels the estimate is too low for households in Omaha. Find the Pvalue for a test of the claim that the proportion with lawn mowers in Omaha is higher than 65%. Among 497 randomly selected homes in Omaha, 340 had one or more lawn mowers. Use Table 5.1 to find the best answer. A. 0.0559 B. 0.1118 C. 0.0252 D. 0.0505 0.0/ 2.5 Points Question 3 of 40 A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO is less than 1 in every one thousand. State the null hypothesis and the alternative hypothesis for a test of significance. A. H0: p = 0.001 Ha: p > 0.001 B. H0: p = 0.001 Ha: p < 0.001 C. H0: p > 0.001 Ha: p = 0.001 D. H0: p < 0.001 Ha: p = 0.001 Question 4 of 40 0.0/ 2.5 Points A researcher wants to check the claim that convicted burglars spend an average of 18.7 months in jail. She takes a random sample of 35 such cases from court files and finds that months. Assume that the population standard deviation is 7 months. Test the null hypothesis that = 18.7 at the 0.05 significance level. A. Do not reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months is supported. B. Do not reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months cannot be supported. C. Reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months is supported. D. Reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months cannot be supported. Question 5 of 40 2.5/ 2.5 Points In the past, the mean running time for a certain type of flashlight battery has been 8.0 hours. The manufacturer has introduced a change in the production method and wants to perform a hypothesis test to determine whether the mean running time has increased as a result. The hypotheses are: H0 : = 8.0 hours Ha : > 8.0 hours Explain the meaning of a Type II error. A. Concluding that > 8.0 hours when in fact > 8.0 hours B. Failing to reject the hypothesis that = 8.0 hours when in fact > 8.0 hours C. Concluding that > 8.0 hours D. Failing to reject the hypothesis that = 8.0 hours when in fact = 8.0 hours 0.0/ 2.5 Points Question 6 of 40 A right-tailed test is conducted at the 5% significance level. Which of the following z-scores is the smallest one in absolute value that leads to rejection of the null hypothesis? A. 1.61 B. 1.85 C. -1.98 D. -2.06 2.5/ 2.5 Points Question 7 of 40 The owner of a football team claims that the average attendance at home games is over 4000, and he is therefore justified in moving the team to a city with a larger stadium. Assume that a hypothesis test of the claim has been conducted and that the conclusion of the test was to reject the null hypothesis. Identify the population to which the results of the test apply. A. All games played by the team in question in which the attendance is over 4000 B. All future home games to be played by the team in question C. All home games played by the team in question D. None of the populations given are appropriate 0.0/ 2.5 Points Question 8 of 40 A researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a mean different from the 600 mg claimed by the manufacturer. Test this claim at the 0.02 level of significance. The mean acetaminophen content for a random sample of n = 41 tablets is 603.3 mg. Assume that the population standard deviation is 4.9 mg. A. Since the test statistic is greater than the critical z, there is sufficient evidence to accept the null hypothesis and to support the claim that the mean content of acetaminophen is 600 mg. B. Since the test statistic is greater than the critical z, there is sufficient evidence to reject the null hypothesis and to support the claim that the mean content of acetaminophen is not 600 mg. C. Since the test statistic is less than the critical z, there is sufficient evidence to reject the null hypothesis and to support the claim that the mean content of acetaminophen is not 600 mg. D. Since the test statistic is greater than the critical z, there is insufficient evidence to reject the null hypothesis and to support the claim that the mean content of acetaminophen is not 600 mg. 0.0/ 2.5 Points Question 9 of 40 A two-tailed test is conducted at the 0.10 significance level. What is the P-value required to reject the null hypothesis? A. Greater than or equal to .010 B. Greater than or equal to 0.05 C. Less than or equal to 0.10 D. Less than or equal to 0.05 Question 10 of 40 2.5/ 2.5 Points A manufacturer claims that the mean amount of juice in its 16 ounce bottles is 16.1 ounces. A consumer advocacy group wants to perform a hypothesis test to determine whether the mean amount is actually less than this. The mean volume of juice for a random sample of 70 bottles was 15.94 ounces. Do the data provide sufficient evidence to conclude that the mean amount of juice for all 16-ounce bottles, , is less than 16.1 ounces? Perform the appropriate hypothesis test using a significance level of 0.10. Assume that = 0.9 ounces. A. The z of 1.49 provides sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz. B. The z of 1.49 does not provide sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz. C. The z of 0.1778 does not provide sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz. D. The z of 0.1778 provides sufficient evidence to conclude that the mean amount of juice is less than 16.1 oz. Question 11 of 40 z = 1.8 for Ha: > claimed value. What is the P-value for the test? A. 0.9641 B. 3.59 C. 96.41 2.5/ 2.5 Points D. 0.0359 Question 12 of 40 0.0/ 2.5 Points In the past, the mean running time for a certain type of flashlight battery has been 9.8 hours. The manufacturer has introduced a change in the production method and wants to perform a hypothesis test to determine whether the mean running time has increased as a result. The hypotheses are: H0 : = 9.8 hours Ha : > 9.8 hours Suppose that the results of the sampling lead to rejection of the null hypothesis. Classify that conclusion as a Type I error, a Type II error, or a correct decision, if in fact the mean running time has not increased. A. Type I error B. Type II error C. Correct decision D. Can not be determined from this information 0.0/ 2.5 Points Question 13 of 40 A long-distance telephone company claims that the mean duration of long-distance telephone calls originating in one town was greater than 9.4 minutes, which is the average for the state. Determine the conclusion of the hypothesis test assuming that the results of the sampling do not lead to rejection of the null hypothesis. A. Conclusion: Support the claim that the mean is less than 9.4 minutes. B. Conclusion: Support the claim that the mean is greater than 9.4 minutes. C. Conclusion: Support the claim that the mean is equal to 9.4 minutes. D. Conclusion: Do not support the claim that the mean is greater than 9.4 minutes. 0.0/ 2.5 Points Question 14 of 40 A two-tailed test is conducted at the 5% significance level. What is the P-value required to reject the null hypothesis? A. Greater than or equal to 0.10 B. Less than or equal to 0.05 C. Less than or equal to 0.10 D. Greater than or equal to 0.05 2.5/ 2.5 Points Question 15 of 40 A psychologist claims that more than 19 percent of the population suffers from professional problems due to extreme shyness. Assume that a hypothesis test of the claim has been conducted and that the conclusion of the test was to reject the null hypothesis. Identify the population to which the results of the test apply. A. The population is all shy workers. B. The population cannot be identified from the description of the study. C. The population is all American workers. D. The population is all American professional workers (doctors, lawyers, CPA's, and the like.. 2.5/ 2.5 Points Question 16 of 40 A poll of 1,068 adult Americans reveals that 52% of the voters surveyed prefer the Democratic candidate for the presidency. At the 0.05 significance level, test the claim that more than half of all voters prefer the Democrat. A. Reject the null hypothesis. Conclude that there is insufficient evidence that more than half of all voters prefer Democrats. B. Do not reject the null hypothesis. Conclude that there is sufficient evidence that more than half of all voters prefer Democrats. C. Reject the null hypothesis. Conclude that there is sufficient evidence that more than half of all voters prefer Democrats. D. Do not reject the null hypothesis. Conclude that there is insufficient evidence that more than half of all voters prefer Democrats. 0.0/ 2.5 Points Question 17 of 40 At one school, the mean amount of time that tenth-graders spend watching television each week is 18.4 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased. Formulate the null and alternative hypotheses for the study described. A. Ho: = 18.4 hours H : 18.4 hours B. Ho: = 18.4 hours H : < 18.4 hours C. Ho: 18.4 hours H : < 18.4 hours D. Ho: = 18.4 hours H : > 18.4 hours 0.0/ 2.5 Points Question 18 of 40 A two-tailed test is conducted at the 5% significance level. Which of the z-scores below is the smallest one that leads to rejection of the null hypothesis? A. 1.12 B. 1.48 C. 1.84 D. 2.15 0.0/ 2.5 Points Question 19 of 40 A supplier of DVDs claims that no more than 1% of the DVDs are defective. In a random sample of 600 DVDs, it is found that 3% are defective, but the supplier claims that this is only a sample fluctuation. At the 0.01 level of significance, test the supplier's claim that no more than 1% are defective. A. Do not reject the null hypothesis and conclude that there is evidence to support the claim that more than 1% of the DVDs are defective. B. Reject the null hypothesis and conclude that there is insufficient evidence to support the claim that more than 1% of the DVDs are defective. C. Do not reject the null hypothesis and conclude that there is insufficient evidence to support the claim that more than 1% of the DVDs are defective. D. Reject the null hypothesis and conclude that there is sufficient evidence to support the claim that more than 1% of the DVDs are defective. Question 20 of 40 0.0/ 2.5 Points If a fan purchased a bag with 30 peanuts, what is the lowest level at which this would be a significant event? A. 0.05 B. 0.025 C. 0.01 D. It is not significant at any of the levels given Part 2 of 2 - Question 21 of 40 0.0/ 50.0 Points 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X 2 statistic is 3.179, state your conclusion about the relationship between gender and colorblindness. A. Do not reject H0. B. Reject H0. C. There is sufficient evidence to support the claim that gender and colorblindness are not related. D. There is not sufficient evidence to accept or reject H0. Question 22 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X2 statistic is 4.613, state your conclusion about the relationship between gender and colorblindness. A. Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related. B. Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related. C. Do not Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related. D. Do not Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related. Question 23 of 40 0.0/ 2.5 Points The following data were analyzed using one-way analysis of variance. A 34 26 31 28 B 27 23 29 21 C 19 21 22 12 Which one of the following statements is correct? A. The purpose of the analysis is to determine whether the groups A, B, and C are independent. B. The purpose of the analysis is to test the hypothesis that the population means of the three groups are equal. C. The purpose of the analysis is to test the hypothesis that the population variances of the three groups are equal. D. The purpose of the analysis is to test the hypothesis that the sample means of the three groups are equal. 0.0/ 2.5 Points Question 24 of 40 A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed. Data from this test resulted in a sample mean of 163.2 yards with a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfer's requirements. Use the partial t-table below to solve this problem. Area in one tail 0.025 0.05 Area in two tails Degrees of Freedom n-1 6 7 8 9 0.05 0.10 2.447 2.365 2.306 2.262 1.943 1.895 1.860 1.833 A. Do not reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 160 yards. B. Reject the null hypothesis. The data does provide sufficient evidence that the average distance is greater than 160 yards. C. t= 1.2334; Critical value = 1.992 D. Insufficient information to answer this question. Question 25 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 15.6 < < 24.8. What is the margin of error? A. 4.4 B. 4.6 C. 4.8 D. 5.0 Question 26 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Male Female Total Colorblind Not Colorblind Total 7 53 60 1 39 40 8 92 100 If gender and colorblindness are independent, find the expected values corresponding to the male combinations of gender and colorblindness. A. Colorblind Male 4.8; Not Colorblind Male 55.2 B. Colorblind Male 6.8; Not Colorblind Male 53.2 C. Colorblind Male 4.8; Not Colorblind Male 55.4 D. Colorblind Male 4.8; Not Colorblind Male 56.2 0.0/ 2.5 Points Question 27 of 40 A golfer wished to find a ball that would travel more than 170 yards when hit with his 6-iron with a club head speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 12 times at the required speed. Data from this test had a sample mean of 171.6 yards with a sample standard deviation of 2.4 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfer's requirements. Use the partial t-table below. Area in one tail 0.025 0.05 Area in two tails Degrees of Freedom n-1 6 7 8 9 0.05 0.10 2.447 2.365 2.306 2.262 1.943 1.895 1.860 1.833 A. Accept the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 170 yards. B. Accept the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 170 yards. C. Reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 170 yards. D. Reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 170 yards. Question 28 of 40 The __________ test statistic is for the one-way analysis of variance. A. P-Value B. t C. F 0.0/ 2.5 Points D. p Question 29 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 15.6 < < 25.2. What is the margin of error? A. 3.9 B. 4.8 C. 4.9 D. 3.7 Question 30 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Male Female Total Colorblind Not Colorblind Total 7 53 60 1 39 40 8 92 100 If gender and colorblindness are independent, find the expected values corresponding to the female combinations of gender and colorblindness. A. Colorblind Female 4.8; Not Colorblind Female 55.2 B. Colorblind Female 3.2; Not Colorblind Female 36.8 C. Colorblind Female 4.8; Not Colorblind Female 35.2 D. Colorblind Female 3.8; Not Colorblind Female 36.2 Question 31 of 40 0.0/ 2.5 Points A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed. State the null and alternative hypotheses for this test. A. H0: = 160; Ha: > 150 B. H0: = 150; Ha: > 150 C. H0: = 160; Ha: > 160 D. H0: = 140; Ha: > 160 Question 32 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 17.6 < < 23.6. What is the margin of error? A. 2.0 B. 2.7 C. 3.0 D. 4.0 Question 33 of 40 0.0/ 2.5 Points A golfer wished to find a ball that would travel more than 180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 7 times at the required speed. Data from this test resulted in a sample mean of 184.2 yards and a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfer's requirements. Use the partial t-table below. Degrees of Area in one tail 0.025 0.05 Area in two tails 0.05 0.10 Freedom n-1 6 7 8 9 2.447 2.365 2.306 2.262 1.943 1.895 1.860 1.833 A. Reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 180 yards. B. Reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 180 yards. C. Do not reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 180 yards. D. Do not reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 180 yards. Question 34 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 13.2 < < 22.4. What is the margin of error? A. 4.6 B. 4.4 C. 4.2 D. 5.6 Question 35 of 40 0.0/ 2.5 Points The margin of error in estimating the population mean of a normal population is E = 9.3 when the sample size is 15. If the sample size had been 25 and the sample standard deviation did not change, would the margin of error be larger or smaller than 9.3? A. Smaller. E increases as the square root of the sample size gets larger. B. Smaller. E decreases as the square root of the sample size gets larger. C. Larger. E decreases as the square root of the sample size gets larger. D. Larger. E increases as the square root of the sample size gets larger. Question 36 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 7 53 60 Female 1 39 40 Total 8 92 100 Find the value of the X2 statistic for the data above. A. 1.325 B. 1.318 C. 1.286 D. 1.264 Question 37 of 40 0.0/ 2.5 Points Which of the following statements is true? A. The t distribution cannot be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population. B. The t distribution can be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population. C. The p distribution can be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population. D. The p distribution can be used when finding a confidence interval for the population mean with a small sample whenever the sample comes from a symmetric population. 0.0/ 2.5 Points Question 38 of 40 A large test statistic F tells us that the sample means __________ the data within the individual samples, which would be unlikely if the populations means really were equal (as the null hypothesis claims). A. differ more than B. differ less than C. are equal to D. do not vary with Question 39 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 8 52 60 Female 2 38 40 Total 10 90 100 State the null and alternative hypothesis for the test associated with this data. A. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are not related in any way. B. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are related in some way. C. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are not related in any way. D. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are related in some way. Question 40 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Male Female Total Colorblind Not Colorblind Total 7 53 60 1 39 40 8 92 100 State the null and alternative hypothesis for the information above. A. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are related in some way. B. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are not related in any way. C. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are not related in any way. D. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are related in some way