Questions and Answers of Essentials Of Statistics

A multiple-choice question on a statistics quiz has possible correct answers of a, b, c, d, e.What is the probability that “false” is the correct answer?
As the author is creating this exercise, a weather reporter stated that there are 3 chances in 10 of rain today. What is the probability of no rain today?
If a day of the week is randomly selected, what is the probability that it is a day containing the letter y?
Based on a Harris poll, 20% of adults smoke. If two adults are randomly selected, what is the probability that they both smoke?
If 1 of the 839 challenges is randomly selected, find the probability of getting a challenge that was rejected.Use the following results from the 839 player challenges to referee calls in the first
If 1 of the 839 challenges is randomly selected, find the probability of getting a challenge that was made by a male player or was rejected.Use the following results from the 839 player challenges to
Find the probability of randomly selecting 1 of the 839 challenges and getting a challenge that was accepted and was made by a female player.Use the following results from the 839 player challenges
Find the probability of randomly selecting 2 different challenges and finding that they were both accepted challenges made by female players.Use the following results from the 839 player challenges
Find the probability of randomly selecting 1 of the 839 challenges and getting a challenge that was accepted, given that it was made by a female player.Use the following results from the 839 player
Find the probability of being sentenced to prison, given that the subject entered a plea of guilty.Use the data in the accompanying table based on data from “Does It Pay to Plead Guilty?
Find the probability of being sentenced to prison, given that the subject entered a plea of not guilty.Use the data in the accompanying table based on data from “Does It Pay to Plead Guilty?
After comparing the results from Exercises 2 and 3, what do you conclude about the wisdom of entering a guilty plea?Use the data in the accompanying table based on data from “Does It Pay to Plead
Before the proliferation of legal lotteries, illegal numbers games were commonly run by members of organized crime groups. In the typical numbers game, bettors would win by selecting the same three
In horse racing, a trifecta is a bet that the first three finishers in a race are selected in the correct order. In a race with 12 horses, how many different trifecta bets are possible? If you
In an Idaho Potato Commission survey of 1000 adults, subjects are asked to select their favorite vegetables, and each response was recorded as “potatoes” or “other.”Determine whether the
In an Idaho Potato Commission survey of 1000 adults, subjects are asked to select their favorite vegetables, and responses of potatoes, corn, broccoli, tomatoes, or “other” were
If the number of blood donors is n = 8, find the probability that the number with Group O blood is x = 3.Assume that when blood donors are randomly selected, 45% of them have blood that is Group O
If the number of blood donors is n = 16, find the probability that the number with Group O blood is x = 6.Assume that when blood donors are randomly selected, 45% of them have blood that is Group O
If the number of blood donors is n = 20, find the probability that the number with Group O blood is x = 16.Assume that when blood donors are randomly selected, 45% of them have blood that is Group O
If the number of blood donors is n = 11, find the probability that the number with Group O blood is x = 9.Assume that when blood donors are randomly selected, 45% of them have blood that is Group O
Use the magnitudes (Richter scale) of the earthquakes listed in Data Set 16 in Appendix B. In 1989, the San Francisco Bay Area was struck with an earthquake that measured 7.0 on the Richter scale.
Carbon monoxide is measured in San Francisco on five different days, and the mean of those five values is 0.62 parts per million. Four of the values (in parts per million) are 0.3, 0.4, 1.1, and 0.7.
The geometric mean is often used in business and economics for finding average rates of change, average rates of growth, or average ratios. Given n values (all of which are positive), the geometric
Which do you think has less variation: the IQ scores of students in your statistics class or the IQ scores of a simple random sample taken from the general population? Why?
James Madison, the fourth President of the United States, was 163 cm tall. His height converts to the z score of -2.28 when included among the heights of all presidents. Is his height above or below
Measures of Location The values of P50, Q2, and the median are found for the net incomes reported on all individual 1040 tax forms filed last year. What do those values have in common?
Based on data from Data Set 17 in Appendix B, the words spoken in a day by women have a mean of 16,215 words and a standard deviation of 7301 words. Consider the women with an unusual word count in a
The following are the duration times (minutes) of all missions flown by the space shuttle Challenger.1 7224 8709 8784 10,060 10,089 10,125 11,445 11,476 11,844Use the given data to construct a
The following are the interval times (minutes) between eruptions of the Old Faithful geyser in Yellowstone National Park based on data from the U.S. National Park Service.81 81 86 87 89 92 93 94 95
The following are amounts of time (minutes) spent on hygiene and grooming in the morning by survey respondents based on data from an SCA survey.4 6 7 9 14 15 15 16 18 18 25 26 30 32 41 45 55 63Use
The following are speeds (mi/h) of cars measured with a radar gun on the New Jersey Turnpike based on data from Statlib and authors Joseph Kadane and John Lamberth.70 70 71 72 72 73 73 74 76 77 78 78
Find the mean of these times that American Airlines flights used to taxi to the Los Angeles terminal after landing from a flight: 12 min, 8 min, 21 min, 17 min, 12 min. Data are from Data Set 15 in
The taxi-in times for 48 flights that landed in Los Angeles have a mean of 11.4 min and a standard deviation of 7.0 min. What is the z score for a taxi-in time of 6 min?
You plan to investigate the variation of taxi-in times for flights that have landed in Los Angeles. Name at least two measures of variation for those data.
Consider a sample taken from the population of all taxi-in times for all flights that land in Los Angeles. Identify the symbols used for the sample mean and the population mean.
Consider a sample taken from the population of all taxi-in times for all flights that land in Los Angeles. Identify the symbols used for the sample standard deviation, the population standard
Approximately what percentage of taxi-in times is less than the 75th percentile?
For a sample of motorcycle speeds, name the values that constitute the 5-number summary
An article in the New York Times noted that these new ZIP codes were created in New York City: 10065, 10021, 10075. Find the mean of these three numbers. What is fundamentally wrong with this result?
Consider the prices of regular movie tickets (not 3-D, and not discounted for children or seniors).a. Estimate the mean price.b. Use the range rule of thumb to make a rough estimate of the standard
Shown below is a boxplot of a sample of 20 brain volumes (cm3). What do the numbers in the boxplot represent? 963 1034.5 1079 1439 1188.5
A statistics class with 40 students consists of 30 students with no income, 10 students with small incomes from part-time jobs, and a professor with a very large income that is well deserved. Which
Currently, there are 4227 Walmart stores in the United States and another 3210 stores outside of the United States.a. Are the numbers of Walmart stores discrete or continuous?b. What is the level of
A survey included 4230 responses from Internet users who decided to respond to a question posted by America OnLine (AOL). Here is the question: How often do you use credit cards for purchases? Among
Survey Identify the type of sampling (random, systematic, convenience, stratified, cluster) used when a sample of the 1500 survey responses is obtained as described. Then determine whether the
Table 2-2 on page 45 is a frequency distribution summarizing the IQ scores of a group of children with low lead exposure. Is it possible to identify the original list of the 78 individual IQ scores
After construction of a relative frequency distribution summarizing the times that males spend each day thinking about females, what should be the sum of the relative frequencies?
A bar chart and a Pareto chart both use bars to show frequencies of categories of categorical data. What characteristic distinguishes a Pareto chart from a bar chart, and how does that characteristic
Listed below are SAT scores from a sample of students (based on data from www.talk.collegeconfidential.com). Why is it that a graph of these data will not be very effective in helping us understand
When one is constructing a table representing the frequency distribution of weights (lb) of discarded textile items from Data Set 23 in Appendix B, the first two classes of a frequency distribution
A stem plot is created from the intervals (min) between eruptions of the Old Faithful geyser in Yellowstone National Park, and one row of that stem plot is 6 | 1222279. Identify the values
In the California Daily 4 lottery, four digits between 0 and 9 inclusive are randomly selected each day. We normally expect that each of the ten different digits will occur about 1/10 of the time,
In an investigation of the travel costs of college students, which of the following does not belong: center; variation; distribution; bar graph; outliers; changing patterns over time?
What characteristic of a data set can be better understood by constructing a histogram?
Which of the following graphs would be best for visually illustrating the data in the table: histogram; dotplot; scatterplot; Pareto chart; stemplot?Refer to the table in the margin, which summarizes
Is the level of measurement of the 641 individual responses nominal, ordinal, interval, or ratio? Why?Refer to the table in the margin, which summarizes results from 641 people who responded to a USA
Misleading Graph How is the accompanying graph misleading? How could it be modified so that it would not be misleading?Refer to the table in the margin, which summarizes results from 641 people who
In conducting a statistical study, why is it important to consider the source of the data?
Correlation and Causation What is meant by the statement that “correlation does not imply causation”?
In a survey of 109 subjects, each was asked to indicate how many text messages they send and receive each day. The sample consisted of those who chose to respond to the request posted on the
In a survey of 514 human resource professionals, each was asked about the importance of the appearance of a job applicant. The survey subjects were randomly selected by Harris Interactive
In a survey of beliefs about evolution, Gallup pollsters randomly selected and telephoned 1018 adults in the United States.Determine whether the sampling method appears to be sound or is flawed.
In a study of the Marisa Waite diet, four subjects lost an average of 45 pounds. It is found that there is about a 30% chance of getting such results with a diet that has no effect.Determine whether
The listed pulse rates were obtained for the Third National Health and Nutrition Examination Survey conducted by the U.S. Department of Health and Human Services, National Center for Health
The data in the table were obtained by members of departments at Harvard Medical School, Massachusetts General Hospital, Dartmouth College, Dartmouth Medical School, and the University of California
If we were to use such data and conclude that there is a correlation or association between IQ score and brain volume, does it follow that larger brains are the cause of higher IQ scores? IQ Score
Parameter and Statistic What is a parameter, and what is a statistic?
Identifying the Population In a Gallup poll of 1010 adults in the United States, 55% of the respondents said that they used local TV stations daily as a source of news. Is the 1010 value a statistic
Distracted Driving In a AAA Foundation for Traffic Safety survey, 21% of the respondents said that they recently texted or e-mailed while driving.Determine whether the given value is a statistic or a
States There are 50 state capitols in the United States.Determine whether the given value is a statistic or a parameter.
Late Flights Among the flights included in the sample of flights in Data Set 15 of Appendix B, 21% arrived late.Determine whether the given value is a statistic or a parameter. Data set name is
IQ Scores The mean IQ score for subjects taking the Wechsler Adult Intelligence Scale IQ test is 100.Determine whether the given value is a statistic or a parameter.
Brain Volume The average (mean) volume of the brains included in Data Set 6 of Appendix B is 1126.0 cm3.Determine whether the given value is a statistic or a parameter. Data Set 6: IQ and Brain Size
HDTV Penetration In a random sample of households, it was found that 47% of the sampled households had high-definition TVs.Determine whether the given value is a statistic or a parameter.
Honda Civic Crash Test In Data Set 13 of Appendix B, the measured chest deceleration of a Honda Civic in a crash test is 39 g, where g is a force of gravity.Determine whether the given values are
Honda Civic Cylinders The Honda Civic has 4 cylinders.Determine whether the given values are from a discrete or continuous data set.
Word Count From Data Set 17 in Appendix B we see that a male spoke 13,825 words in one day.Determine whether the given values are from a discrete or continuous data set. Data Set 17: Word Counts by
First President George Washington was 188 cm tall.Determine whether the given values are from a discrete or continuous data set.
House of Representatives Currently the House of Representatives has 435 members.Determine whether the given values are from a discrete or continuous data set.
Crash Test Results Data Set 13 in Appendix B includes crash test results from 21 different cars.Determine whether the given values are from a discrete or continuous data set. Data Set 13: Car Crash
Earthquake From Data Set 16 in Appendix B we see that an earthquake had a measurement of 0.70 on the Richter scale.Determine whether the given values are from a discrete or continuous data set. Data
Arm Circumference From Data Set 1 in Appendix B we see that a female had an arm circumference of 27.5 cm.Determine whether the given values are from a discrete or continuous data set. Data Set 1:
Years in which U.S. presidents were inaugurated. Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.
The movie Avatar was given a rating of 4 stars on a scale of 5 stars.Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.
Volumes (cm3) of brains listed in Data Set 6 of Appendix B. Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. Data Set 6: IQ and Brain Size
Car models (Chevrolet Aveo, Honda Civic, . . . , Buick Lucerne) used for crash testing, as listed in Data Set 13 of Appendix B. Determine which of the four levels of measurement (nominal, ordinal,
Political Parties In a preelection survey of likely voters, political parties of respondents are identified as 1 for a Democrat, 2 for a Republican, 3 for an Independent, and 4 for anything else. The
Flight Numbers Data Set 15 in Appendix B lists flight numbers of 48 different flights, and the average (mean) of those flight numbers is 11.0.Identify the level of measurement of the data. Also,
World Series Champs As of this writing, the New York Yankees were the last team to win the World Series, and the numbers of the starting lineup are 2, 18, 25, 13, 20, 55, 24, 33, and 53. The average
The Milgram Research Company wants to study reactions to stress, so it administers surveys in which the person asking the questions pretends to become very angry with the survey subject. At one
In a clinical trial of the cholesterol drug Lipitor, 188 subjects were given 20-mg doses of the drug, and 3.7% of them experienced nausea (based on data from Pfizer, Inc.).Determine whether the given
In a study sponsored by Coca-Cola, 12,500 people were asked what contributes most to their happiness, and 77% of the respondents said that it was their family or partner.Determine whether the given
The author collected sample data by randomly selecting 12 different pages from Harry Potter and the Sorcerer’s Stone and then finding the number of words in each sentence on each of those
In a Pew Research Center poll, 1007 adults were called after their telephone numbers were randomly generated by a computer, and 85% of the respondents were able to correctly identify what Twitter
When collecting data from different sample locations in a lake, a researcher uses the “line transect method” by stretching a rope across the lake and collecting samples at every interval of 5
The CBS News station in New York City often obtains opinions by interviewing neighbors of a person who is the focus of a news story.Identify which of these types of sampling is used: random,
The author collected sample data by randomly selecting 20 different pages from a printed version of the Merriam-Webster Dictionary and then counting the number of defined words on each of those
The New York State Department of Transportation evaluated the quality of the New York State Throughway by testing core samples collected at regular intervals of one mile.Identify which of these types
In order to test for a gender gap in the way that men and women purchase cars, the Grant Survey Company polls exactly 750 adult men and 750 adult women randomly selected from adults in the United
According to the State of New York Unified Court System, names of potential jurors are selected from a variety of different sources. When a trial requires a jury, names from the list are randomly

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