The probability that a randomly selected person has high blood pressure (the event H) is P(H) = 0.5 and the probability that a randomly selected person is a runner (the event R) is P(R) = 0.2. The probability that a randomly selected person has high blood pressure and is a runner is 0.1. Find the probability that a randomly selected person either has high blood pressure or is a runner or both. a) 0.9 b) 0.7 c) 0.5 d) 0.2 e) 0.6 f) None of the above. Review Later Question 2 Among 6 electrical components exactly one is known not to function properly. If 4 components are selected randomly, find the probability that exactly one does not function properly. a) 0.6667 b) 0.5000 c) 0.5787 d) 0.8333 e) 0.3333 f) None of the above Question 3 Given the following sampling distribution: 11 3 11 16 16 P(X 1 3 __ 20 100 120 9100 ) _ X Review Later What is P(X > 11)? a) 0.95 b) 0.92 c) 0.94 d) 0.90 e) 0.91 f) None of the above Review Later Question 4 Suppose you have a distribution, X, with mean = 5 and standard deviation = 4. Define a new random variable Y = 8X 5. Find the mean and standard deviation of Y. a) E[Y] = 35; Y = 32 b) E[Y] = 40; Y = 27 c) E[Y] = 35; Y = 256 d) E[Y] = 40; Y = 256 e) E[Y] = 35; Y = 27 f) None of the above Review Later Question 5 In testing a certain kind of missile, target accuracy is measured by the average distance X (from the target) at which the missile explodes. The distance X is measured in miles and the sampling distribution of X is given by: X 0 10 50 100 P(X 1 1 1 33 40 20 10 40 ) Calculate the variance of this sampling distribution. a) 27.6 b) 5138.7 c) 761.0 d) 253.7 e) 88.0 f) None of the above Review Later Question 6 In testing a certain kind of missile, target accuracy is measured by the average distance X (from the target) at which the missile explodes. The distance X is measured in miles and the sampling distribution of X is given by: X 0 10 50 100 P(X 1 1 2 27 34 17 17 34 ) Calculate the mean of this sampling distribution. a) 29.4 b) 87.4 c) 83.4 d) 865.4 e) 85.9 f) None of the above Review Later Question 7 Test grades on the last statistics exam had a mean = 78 and standard deviation = .14. Suppose the teacher decides to curve by subtraction 31 from all scores then doubling the values. If Y represents the new test scores, what is the mean and standard deviation of Y? a) E[Y] = 156; Y = .56 b) E[Y] = 94; Y = 61.72 c) E[Y] = 125; Y = .28 d) E[Y] = 47; Y = 30.72 e) E[Y] = 94; Y = .28 f) None of the above Review Later Question 8 In testing a new drug, researchers found that 5% of all patients using it will have a mild side effect. A random sample of 5 patients using the drug is selected. Find the probability that exactly two will have this mild side effect. a) 0.03143 b) 0.02143 c) 0.07143 d) 0.06143 e) 0.05143 f) None of the above Review Later Question 9 A manufacturer of matches randomly and independently puts 21 matches in each box of matches produced. The company knows that onetenth of 8 percent of the matches are flawed. What is the probability that a matchbox will have one or fewer matches with a flaw? a) 0.006813 b) 0.9878 c) 0.9920 d) 0.1431 e) 0.8448 f) None of the above Review Later Question 10 Each year a company selects a number of employees for a management training program. On average, 40 percent of those sent complete the program. Out of the 41 people sent, what is the probability that exactly 8 complete the program? a) 0.0469 b) 0.0044 c) 0.1044 d) 0.2029 e) 0.0029 f) None of the above Review Later Question 11 A quarter back completes 62% of his passes. We want to observe this quarterback during one game to see how many pass attempts he makes before completing one pass. What is the probability that the quarterback throws 4 incomplete passes before he has a completion? a) 0.0129 b) 0.0049 c) 0.9870 d) 0.9950 e) 0.0269 f) None of the above Review Later Question 12 The length of time needed to complete a certain test is normally distributed with mean 74 minutes and standard deviation 12 minutes. Find the probability that it will take less than 88 minutes to complete the test. a) 0.4392 b) 0.8783 c) 0.5608 d) 0.1217 e) 0.5000 f) None of the above Question 13 Find a value of c so that P(Z c) = 0.43. a) 1.18 b) 0.18 c) 0.32 d) 0.82 e) 0.18 f) None of the above Review Later Review Later Question 14 A random sample of 1024 12ounce cans of fruit nectar is drawn from among all cans produced in a run. Prior experience has shown that the distribution of the contents has a mean of 12 ounces and a standard deviation of 0.12 ounce. What is the probability that the mean contents of the 1024 sample cans is less than 11.994 ounces? a) 0.085 b) 0.095 c) 0.055 d) 0.075 e) 0.065 f) None of the above Review Later Question 15 Lloyd's Cereal company packages cereal in 1 pound boxes (16 ounces). A sample of 25 boxes is selected at random from the production line every hour, and if the average weight is less than 15 ounces, the machine is adjusted to increase the amount of cereal dispensed. If the mean for 1 hour is 1 pound and the standard deviation is 0.1 pound, what is the probability that the amount dispensed per box will have to be increased? a) 0.2660 b) 0.0009 c) 0.2009 d) 0.9991 e) 0.0018 f) None of the above Review Later Question 16 In a large population, 91% of the households have cable tv. A simple random sample of 144 households is to be contacted and the sample proportion computed. What is the mean and standard deviation of the sampling distribution of the sample proportions? a) [0.91, 0.0795] b) [0.1092, 0.0238] c) [0.91, 0.0238] d) [91, 0.0795] e) [91, 0.0238] f) None of the above Review Later Question 17 In a large population, 72% of the households have cable tv. A simple random sample of 100 households is to be contacted and the sample proportion computed. What is the probability that the sampling distribution of sample porportions is less than 68%? a) 0.1865 b) 0.3187 c) 0.0932 d) 0.6813 e) 0.8135 f) None of the above Review Later Question 18 Determine the correlation coefficient for the data shown in this table: x 2 7 8 y 23 28 29 11 40 17 28 16 42 a) 0.6047 b) 0.3656 c) 0.3023 d) 0.3656 e) 0.6047 f) None of the above Review Later Question 19 Which of the following would be the LSRL for the given data? 11 x 3 6 y 43 37 29 13 22 a) = b) = c) = d) = e) None of the above 16 22 18 11 Review Later Question 20 Suppose you have the following data: x 1 2 3 4 5 6 y 44 37 27 21 22 14 and the LSRL is = x = 1. a) . Find the residual value for b) c) d) e) None of the above Review Later Question 21 The following twoway table describes the preferences in movies and fast food restaurants for a random sample of 100 people. McDonald's Taco Bell Wendy's 20 15 5 Iron Man Dispicable 12 Me Harry Potter 9 7 9 11 12 What percent of the Dispicable Me lovers also like McDonald's? a) 43% b) 40% c) 9% d) 22% e) 21% Review Later Question 22 A simple random sample of 100 8th graders at a large suburban middle school indicated that 81% of them are involved with some type of after school activity. Find the 98% confidence interval that estimates the proportion of them that are involved in an after school activity. a) [0.719, 0.901] b) [0.769, 0.774] c) [0.639, 0.901] d) [0.719, 0.701] e) [0.619, 0.851] f) None of the above Review Later Question 23 It has been observed that some persons who suffer acute heartburn, again suffer acute heartburn within one year of the first episode. This is due, in part, to damage from the first episode. The performance of a new drug designed to prevent a second episode is to be tested for its effectiveness in preventing a second episode. In order to do this two groups of people suffering a first episode are selected. There are 108 people in the first group and this group will be administered the new drug. There are 170 people in the second group and this group wil be administered a placebo. After one year, 12% of the first group has a second episode and 14% of the second group has a second episode. Select a 99% confidence interval for the difference in true proportion of the two groups. a) [0.147, 0.107] b) [0.126, 0.086] c) [0.107, 0.147] d) [0.086, 0.126] e) [0.626, 0.586] f) None of the above Review Later Question 24 It has been observed that some persons who suffer from common colds are diagnosed with it again within one year of the first episode. This is due, in part, to damage from the first episode. In order to examine the percentage of the persons who suffer from common colds a second time, a random sample of 1000 people who suffered from common colds was collected. It was observed that 14 of them again suffered from common colds within one year. Select a 90% confidence interval for the true proportion of those who suffer a second episode. a) [0.0129, 0.0301] b) [0.00786, 0.0201] c) [0.00886, 0.0701] d) [0.0109, 0.0501] e) [0.00886, 0.0401] f) None of the above Review Later Question 25 The gas mileage for a certain model of car is known to have a standard deviation of 5 mi/gallon. A simple random sample of 100 cars of this model is chosen and found to have a mean gas mileage of 26.5 mi/gallon. Construct a 98% confidence interval for the mean gas mileage for this car model. a) [25.473, 27.527] b) [14.870, 38.130] c) [25.337, 27.663] d) [26.384, 26.616] e) [16.230, 36.770] f) None of the above Review Later Question 26 Location is known to affect the number, of a particular item, sold by HEB Pantry. Two different locations, A and B, are selected on an experimental basis. Location A was observed for 18 days and location B was observed for 13 days. The number of the particular items sold per day was recorded for each location. On average, location A sold 39 of these items with a sample standard deviation of 8 and location B sold 49 of these items with a sample standard deviation of 4. Select a 99% confidence interval for the difference in the true means of items sold at location A and B. a) [12.42, 7.582] b) [32.76, 45.24] c) [81.76, 94.24] d) [16.03, 3.97] e) [42.76, 55.24] f) None of the above Review Later Question 27 An oil company is interested in estimating the true proportion of female truck drivers based in five southern states. A statistician hired by the oil company must determine the sample size needed in order to make the estimate accurate to within 2% of the true proportion with 98% confidence. What is the minimum number of truck drivers that the statistician should sample in these southern states in order to achieve the desired accuracy? a) 3382 b) 3390 c) 3364 d) 3374 e) 3397 f) None of the above Review Later Question 28 An experimenter flips a coin 100 times and gets 34 heads. Test the claim that the coin is fair against the twosided claim that it is not fair at the level =.01. a) Ho: p = .5, Ha: p .5; z = 3.20; Reject Ho at the 1% significance level. b) Ho: p = .5, Ha: p .5; z = 3.20; Fail to reject Ho at the 1% significance level. c) Ho: p = .5, Ha: p < .5; z = 3.20; Fail to reject Ho at the 1% significance level. d) Ho: p = .5, Ha: p .5; z = 3.38; Reject Ho at the 1% significance level. e) Ho: p = .5, Ha: p < .5; z = 3.38; Reject Ho at the 1% significance level. Review Later Question 29 A private and a public university are located in the same city. For the private university, 1048 alumni were surveyed and 647 said that they attended at least one class reunion. For the public university, 797 out of 1319 sampled alumni claimed they have attended at least one class reunion. Is the difference in the sample proportions statistically significant? (Use =0.05) a) Reject the null hypothesis which states there is no difference in the proportion of alumni that attended at least one class reunion in favor of the alternate which states there is a difference in the proportions. b) Fail to reject the null hypothesis. There is not enough evidence to conclude that there is a difference in the proportions. c) There is not enough information to make a conclusion. Review Later Question 30 Mars Inc. claims that they produce M&Ms with the following distributions: 20% 25% Yellow 25% Red Orange Green 15% 10% 5% Blue Brown A bag of M&Ms was randomly selected from the grocery store shelf, and the color counts were: 25 23 Yellow 21 Red Orange 13 Green 15 14 Blue Brown Using the 2 goodness of fit test ( = 0.05) to determine if the proportion of M&Ms is what is claimed. Select the [test statistic, p value, Decision to Reject (RH0) or Failure to Reject (FRH0)]. a) [2 = 6.865, pvalue = 0.983, RH0] b) [2 = 13.730, pvalue = 0.009, RH0] c) [2 = 13.730, pvalue = 0.017, RH0] d) [2 = 13.730, pvalue = 0.017, FRH0] e) [2 = 6.865, pvalue = 0.983, FRH0] f) None of the above Review Later Question 31 It has been observed that some persons who suffer colitis, again suffer colitis within one year of the first episode. This is due, in part, to damage from the first episode. The performance of a new drug designed to prevent a second episode is to be tested for its effectiveness in preventing a second episode. In order to do this two groups of people suffering a first episode are selected. There are 75 people in the first group and this group will be administered the new drug. There are 45 people in the second group and this group will be administered a placebo. After one year, 11% of the first group has a second episode and 9% of the second group has a second episode. Conduct a hypothesis test to determine, at the significance level 0.05, whether there is reason to believe that the true percentage of those in the first group who suffer a second episode is less than the true percentage of those in the second group who suffer a second episode? Select the [Rejection Region, Decision to Reject (RH0) or Failure to Reject (FRH0)]. a) [z < 1.65 or z > 1.65, FRH0] b) [z > 1.65, RH0] c) [z > 1.65 and z < 1.65, RH0] d) [z < 1.65 and z > 1.65, FRH0] e) [z < 1.65, FRH0] f) None of the above Review Later Question 32 An auditor for a hardware store chain wished to compare the efficiency of two different auditing techniques. To do this he selected a sample of nine store accounts and applied auditing techniques A and B to each of the nine accounts selected. The number of errors found in each of techniques A and B is listed in the table below: Errors in A 27 30 Errors in B 13 19 28 30 34 32 31 22 27 21 19 36 27 31 23 32 Does the data provide sufficient evidence to conclude that the number of errors in auditing technique A is fewer than the number of errors in auditing technique B at the 0.01 level of significance? Select the [Alternative Hypothesis, Value of the Test Statistic]. (Hint: the samples are dependent) a) [A < B, 1.976] b) [D 0, 1.976] c) [D = 0, 1.976] d) [D < 1, 1.976] e) [D < 0, 1.976] f) None of the above Review Later Question 33 An experimenter flips a coin 100 times and gets 43 heads. Test the claim that the coin is fair against the twosided claim that it is not fair at the level =.01. a) Ho: p = .5, Ha: p < .5; z = 1.41; Fail to reject Ho at the 1% significance level. b) Ho: p = .5, Ha: p < .5; z = 1.40; Reject Ho at the 1% significance level. c) Ho: p = .5, Ha: p .5; z = 1.40; Fail to reject Ho at the 1% significance level. d) Ho: p = .5, Ha: p .5; z = 1.40; Reject Ho at the 1% significance level. e) Ho: p = .5, Ha: p .5; z = 1.41; Fail to reject Ho at the 1% significance level. Review Later Question 34 Identify the most appropriate test to use for the following situation: In a experiment on relaxation techniques, subject's brain signals were measured before and after the relaxation exercises. We wish to determine if the relaxation exercise slowed the brain waves. a) Matched pairs b) One sample t test c) Two sample t test d) Two sample p test Review Later Question 35 It has been observed that some persons who suffer renal failure, again suffer renal failure within one year of the first episode. This is due, in part, to damage from the first episode. The performance of a new drug designed to prevent a second episode is to be tested for its effectiveness in preventing a second episode. In order to do this two groups of people suffering a first episode are selected. There are 31 people in the first group and this group will be administered the new drug. There are 45 people in the second group and this group will be administered a placebo. After one year, 11% of the first group has a second episode and 9% of the second group has a second episode. Conduct a hypothesis test to determine, at the significance level 0.1, whether there is reason to believe that the true percentage of those in the first group who suffer a second episode is more than the true percentage of those in the second group who suffer a second episode? Select the [Alternative Hypothesis, Value of the Test Statistic]. a) [p1 = p2 , 0.2880] b) [p1 > p2 , 0.2880] c) [p1 p2 , 0.3880] d) [p1 p2 , 0.2880] e) [p1 < p2 , 0.2880] f) None of the above