AP Statistics Fall Final Review

Section 2.2 The weights of 9-ounce bags of a particular brand of potato chips can be modeled by a Normal distribution with mean mu = 9.12 ounces and standard deviation sigma = 0.05 ounce. Using the 68-95-99.7 rule, a bag that weighs 9.07 ounces is at about what percentile in this distribution?

16th percentile

Section 2.2 A study investigated about 3000 meals ordered from Chipotle restaurants using the online site Grubhub. Researchers calculated the sodium content (in milligrams) for each order based on Chipotle's published nutrition information. The distribution of sodium content is approximately Normal with mean 2000 mg and standard deviation 500 mg. About what percent of the meals ordered exceeded the recommended daily allowance of 2400 mg of sodium?

21.20%

Section 1.3 The stemplot shows the number of home runs hit by each of the 30 Major League Baseball teams in a single season. Home run totals above what value should be considered outliers?

257

Section 1.3 The histogram shows the distribution of lengths of words used in Shakespeare's plays. What is the median word length?

4

Section 2.1 How many pairs of shoes does a typical teenage boy own? To find out, two AP Statistics students surveyed a random sample of 20 male students from their large high school. Then they recorded the number of pairs of shoes that each boy owned. Given is a dotplot of the data. One of the students, Jackson, reported owning 22 pairs of shoes. What is Jackson's percentile?

85th percentile

Section 2.1 The figure is a cumulative relative frequency graph of the amount spent by 50 consecutive grocery shoppers in a store. What is the percentile for the shopper who spent $19.50?

The 26th percentile

Section 1.2 The stemplot displays data on the amount spent by 50 shoppers at a grocery store. Note that the values have been rounded to the nearest dollar. Which of the following is not a correct description of the distribution of the amount spent by the 50 shoppers at the grocery store?

The amount of dollars spent varies from about $3.99 to $93.00.

Section 1.3 Joey's first 14 quiz grades in a marking period were as follows: What is the mean of Joey's quiz grades?

85

Section 2.2 Find the proportion of observations that satisfies -1.66 < z < 2.85.

NOT 99.78% NOT 95.15%

Section 1.2 Here are the weights (in grams) of 17 Snickers® Fun Size bars from a single bag: Make a proper stemplot of the data.

-Should have 15, 16, 17, 18, 19 in left column. -Should have 17 | 1 1 1 -Should have key

Section 2.2 Professional tennis player Novak Djokovic hits the ball extremely hard. His first-serve speeds can be modeled by a Normal distribution with mean 112 miles per hour (mph) and standard deviation 5 mph. Find the 85th percentile of Djokovic's first-serve speeds.

117.2 mph

Section 1.2 Researchers asked the students in a large first-year college class how many minutes they studied on a typical weeknight. The back-to-back stemplot displays the responses from random samples of 30 women and 30 men from the class, rounded to the nearest 10 minutes. Which of the following are correct comparisons of the distributions of study time for men and for women.

I and II only

Section 3.1 The scatterplot shows the relationship between the amount of fat (in grams) and number of calories in products sold at Starbucks. Describe the relationship between fat and calories for these products.

There is a moderately strong, positive, linear relationship between amount of fat and number of calories in Starbucks products.

Section 1.2 Here is a stemplot of the percent of residents aged 25 to 34 in each of the 50 states. Give an appropriate key for this stemplot.

16 | 0 means that 16.0% of the state's residents are aged 25 to 34.

Section 2.2 According to a health information website, the distribution of adults' diastolic blood pressure (in millimeters of mercury) can be modeled by a Normal distribution with mean 70 and standard deviation 20. A diastolic pressure above 100 for an adult is classified as very high blood pressure. About what percentage of adults have very high blood pressure according to this criterion?

6.70%

Section 1.0 Here is a small part of the data set that describes the students in an AP Statistics class. The data come from anonymous responses to a questionnaire filled out on the first day of class. The individuals in this data set are

AP Statistics students

Section 3.1 The yield of corn in bushels per acre and the amount of rain in the growing season Identify the explanatory variable and the response variable, if possible.

Amount of rain is the explanatory variable and yield of corn is the response variable

Section 2.2 The following figure is a Normal probability plot of the heart rates of 200 male runners after 6 minutes of exercise on a treadmill. What is the shape of the distribution of heart rates?

Approximately Normal

Section 1.3 The parallel dotplots show the lengths (in millimeters) of a sample of 11 nails produced by each of two machines. Which distribution has the largest standard deviation? How do you know?

Machine B has a larger standard deviation because more of the observations have values farther from the mean than in Machine A's distribution.

Section 2.2 The figure below displays a density curve that models a distribution of quantitative data. Identify the location of the mean and median by letter for the graph.

Mean is A, median is A

Section 1.3 A study in Switzerland examined the number of cesarean sections (surgical deliveries of babies) performed in a year by samples of male and female doctors. Here are the summary statistics for the two distributions: Which of the following statements is incorrect?

NOT Male doctors have a larger range than female doctors.

Section 2.2 Two measures of center are marked on the density curve shown. Which of the following is correct?

The median is at the red line and the mean is at the yellow line.

Section 2.1 Jorge's score on Exam 1 in his statistics class was at the 64th percentile of the scores for all students. His score falls

between the median and the third quartile

Section 1.2 How old is the oldest person you know? Prudential Insurance Company asked 400 people to place a blue sticker on a huge wall next to the age of the oldest person they have ever known. An image of the graph is shown here. Describe the shape of this distribution.

Left skewed with a single peak between 90 and 100.

Section 1.2 The histogram shows the heights of 300 randomly selected high school students. Which of the following is the best description of the shape of the distribution of the heights?

Roughly symmetric and single peaked.

Section 1.2 The dotplot shows the results of rolling a pair of fair, six-sided dice and finding the sum of the up-faces 100 times. Describe the shape of this distribution.

Symmetric with a single peak at 7.

Section 1.2 Here is a stemplot of the areas of the 46 counties in South Carolina. Note that the data have been rounded to the nearest 10 square miles (mi2). What is the area of the largest South Carolina county?

1,220 square miles

Section 2.2 Mrs. Starnes enjoys doing Sudoku puzzles. The time she takes to complete an easy puzzle can be modeled by a Normal distribution with mean 5.3 minutes and standard deviation 0.9 minute. Find the 20th percentile of Mrs. Starnes' Sudoku times for easy puzzles.

4.54 minutes

Section 3.1 Here is a scatterplot showing the relationship between the number of turnovers and the number of points scored for players in a recent NBA season. The correlation for these data is r = 0.92. Interpret the correlation.

The correlation of 0.92 indicates that the linear relationship between number of turnovers and number of points scored for players in the 2013 NBA season is strong and positive.

Section 1.3 How much storage space does your music use? Here is a dotplot of the file sizes (to the nearest tenth of a megabyte) for 18 randomly selected files on Nathaniel's mp3 player: The distribution of file size has a mean of Suppose the music file that takes up 7.5 megabytes of storage space is replaced with another version of the file that only takes up 4 megabytes. How would this affect the mean and standard deviation?

The mean would decrease and the standard deviation would decrease.

Section 1.3 To become the president of the United States, a candidate does not have to receive a majority of the popular vote. The candidate does have to win a majority of the 538 Electoral College votes. Here is a stemplot of the number if electoral votes in 2016 for each of the 50 states and the District of Columbia. Below are a boxplot and some numerical summaries of the electoral vote data. Without doing additional calculations, which of the following is an aspect of this distribution that the stemplot reveals but the boxplot does not?

The stemplot reveals that the distribution has a single peak.

Section 2.2 The figure displays a density curve that models a distribution of quantitative data. Identify the location of the mean and median by letter for the graph.

NOT Mean is A, median is B NOT Mean is C, median is A

Section 2.2 A study investigated about 3000 meals ordered from Chipotle restaurants using the online site Grubhub. Researchers calculated the sodium content (in milligrams) for each order based on Chipotle's published nutrition information. The distribution of sodium content is approximately Normal with mean 2000 mg and standard deviation 500 mg. About what percent of meals ordered contained between 1200 mg and 1800 mg of sodium?

29%

Section 1.3 Joey's first 14 quiz grades in a marking period were as follows: Suppose Joey has an unexcused absence for the 15th quiz, and he receives a score of 0. What is the new mean of Joey's quiz grades? What property of the mean does this illustrate?

79.3; This shows that the mean is nonresistant to outliers.

Section 1.3 The scores on a statistics test had a mean of 81 and a standard deviation of 9. One student was absent on the test day, and his score wasn't included in the calculation. If his score of 84 was added to the distribution of scores, what would happen to the mean and standard deviation?

Mean will increase, and standard deviation will decrease.

Section 1.2 Nitrates are organic compounds that are a main ingredient in fertilizers. When those fertilizers run off into streams, the nitrates can have a toxic effect on fish. An ecologist studying nitrate pollution in two streams measures nitrate concentrations at 42 places on Stony Brook and 42 places on Mill Brook. The parallel dotplots display the data. Which of the following is a correct comparison of the distributions of nitrate concentration in these two streams?

NOT The median nitrate concentration for the two streams are about the same. NOT Both distributions appear to be right-skewed.

Section 1.3 Researchers recorded data on the amount of sleep reported each night during a week by a random sample of 20 high school students. Here are parallel boxplots comparing the distribution of time slept on all 7 nights of the study: On which night was there the most variation in the amount of time that the students slept? Justify your answer.

On Friday.

Section 2.1 Many professional schools require applicants to take a standardized test. Suppose that 1000 students take such a test. Several weeks after the test, Pete receives his score report: he got a 63, which placed him at the 73rd percentile. This means that

Pete did better than about 73% of the test takers.

Section 1.3 The figure displays computer output for data on the amount spent by 50 grocery shoppers. Based only on the computer output, what should you expect the shape of the distribution to be? Explain why.

Skewed to the right because the mean is larger than the median.

Section 3.1 Archaeopteryx is an extinct beast that had feathers like a bird but teeth and a long bony tail like a reptile. Only six fossil specimens are known to exist today. Because these specimens differ greatly in size, some scientists think they are different species rather than individuals from the same species. If the specimens belong to the same species and differ in size because some are younger than others, there should be a positive linear relationship between the lengths of a pair of bones from all individuals. An outlier from this relationship would suggest a different species. Here are data on the lengths (in centimeters) of the femur (a leg bone) and the humerus (a bone in the upper arm) for the five specimens that preserve both bones: Find the correlation. Explain how your value for r matches the scatterplot below.

The correlation coefficient is r = 0.9941

Section 1.2 How long do people travel each day to get to work? Here is a histogram displaying the average travel times to work (in minutes) for workers in each state and the District of Columbia who are at least 16 years old and don't work at home. Which statement about the shape and center of the histogram is true?

The distribution of travel times is roughly symmetric and the most common interval of travel times is 22 to 24 minutes.

Section 3.1 You have data for many years on the average price of a barrel of oil and the average retail price of a gallon of unleaded regular gasoline. If you want to see how well the price of oil predicts the price of gas, then you should make a scatterplot with _____ as the explanatory variable.

the price of oil

Section 1.3 Which of the following boxplots best matches the distribution shown in the histogram?

-Longest box (IQR)

Section 2.1 According to a study by Nielsen Mobile, "Teenagers 13 to 17 are by far the most prolific texters, sending 1742 messages a month." Mr. Williams, a high school statistics teacher, was skeptical about the claims in the article. So he collected data from his first-period statistics class on the number of text messages they had sent over the past 24 hours. Given are the data. How many text messages did Joelle, who is at the 16th percentile of the distribution, send?

1 text message

Section 2.2 Scores on the Wechsler Adult Intelligence Scale (an IQ test) for the 20- to 34-year-old age group are approximately Normally distributed with mu = 110 and sigma = 25. MENSA is an elite organization that admits as members people who score in the top 2% on IQ tests. What score on the Wechsler Adult Intelligence Scale would an individual aged 20 to 34 have to earn to qualify for MENSA membership?

130.9

Section 2.1 The cumulative frequency graph shows the distribution of the percent of foreign-born residents in the 50 states. Estimate the interquartile range (IQR) of this distribution.

14% - 4% = 10%

Section 2.1 Scores on the ACT college entrance exam follow a bell-shaped distribution with mean 21 and standard deviation 5. Wayne's standardized score on the ACT was -0.6. What was Wayne's actual ACT score?

18

Section 1.3 We all know that fruit is good for us. Here is a histogram of servings of fruit per day claimed by 74 seventeen-year-old girls in a study in Pennsylvania. What is the median number of servings of fruit per day?

2

Section 2.2 The weights of 9-ounce bags of a particular brand of potato chips can be modeled by a Normal distribution with mean mu = 9.12 ounces and standard deviation sigma = 0.05 ounce. Using the 68-95-99.7 rule, about what percent of bags weigh less than 9.02 ounces?

2.50%

Section 2.2 Mrs. Starnes enjoys doing Sudoku puzzles. The time she takes to complete an easy puzzle can be modeled by a Normal distribution with mean 5.3 minutes and standard deviation 0.9 minute. What percent of easy Sudoku puzzles take Mrs. Starnes between 6 and 8 minutes to complete?

21.64%

Section 2.1 According to a study by Nielsen Mobile, "Teenagers 13 to 17 are by far the most prolific texters, sending 1742 messages a month." Mr. Williams, a high school statistics teacher, was skeptical about the claims in the article. So he collected data from his first-period statistics class on the number of text messages they had sent over the past 24 hours. Given are the data. Sunny was the student who sent 42 text messages. What is Sunny's percentile?

72nd percentile

Section 1.3 Here are the data on resting pulse rates (in beats per minute) of 19 middle school students: The student with a 120 pulse rate has a medical issue. What is the median pulse rate excluding the student with the medical issue? What property of the mean does this illustrate?

76; the median is resistant

Section 1.3 Here are the data on resting pulse rates (in beats per minute) of 19 middle school students: The student with a 120 pulse rate has a medical issue. What is the mean pulse rate for the other 18 students? What property of the mean does this illustrate?

79.06; the mean is nonresistant

Section 1.3 Here are the data on resting pulse rates (in beats per minute) of 19 middle school students: What is the mean pulse rate?

81.21 bpm

Section 1.3 Joey's first 14 quiz grades in a marking period were as follows: What is the median of Joey's quiz grades?

85

Section 3.1 Measurements on young children in Mumbai, India, found this least-squares line for predicting y = height (in cm) from x = arm span (in cm). y = 6.4 + 0.93x In addition to the regression line, the report on the Mumbai measurements says that

95% of the variation in height is accounted for by the regression line with x = arm span.

Section 2.1 George's average bowling score is 180; he bowls in a league where the average for all bowlers is 150 and the standard deviation is 20. Bill's average bowling score is 190; he bowls in a league where the average is 160 and the standard deviation is 15. Who ranks higher in his own league, George or Bill?

Bill, because his standardized score is higher than George's.

Section 2.1 Three landmarks of baseball achievement are Ty Cobb's batting average of 0.420 on 1911, Ted Williams's 0.406 in 1941, and George Brett's 0.390 in 1980. These batting averages cannot be compared directly because the distribution of major league batting averages has changed over the years. The distributions are quite symmetric, except for outliers such as Cobb, Williams, and Brett. While the mean batting average has been held roughly constant by rule changes and the balance between hitting and pitching, the standard deviation has dropped over time. Here are the facts: Find the standardized scores for Cobb, Williams, and Brett. Who had the best performance for the decade he played?

Cobb: z = 4.15

Section 1.0 Many people like to ride roller coasters. Amusement parks try to increase attendance by building exciting new coasters. The following table displays data on several roller coasters that were opened in a recent year. Which of the following is not a quantitative variable?

Design

Section 2.1 Eleanor scores 680 on the SAT Mathematics test. The distribution of the SAT Math scores is symmetric and single-peaked with mean 500 and standard deviation 100. Gerald takes the American College Testing (ACT) Mathematics test and scores 29. ACT scores also follow a symmetric, single-peaked distribution - but with mean = 21 and standard deviation = 5. Find the standardized scores for both students. Assuming that both tests measure the same kind of ability, who has the higher score?

Eleanor: z = 1.8

Section 1.3 Researchers recorded data on the amount of sleep reported each night during a week by a random sample of 20 high school students. Here are parallel boxplots comparing the distribution of time slept on all 7 nights of the study: Which outlier stands out the most? Why?

Friday.

Section 2.1 Until the scale was changed in 1995, SAT scores were based on a scale set many years ago. For Math scores, the mean under the old scale in the early 1990s was 470 and the standard deviation was 110. In 2016, the mean was 510 and the standard deviation was 103. Gina took the SAT in 1994 and scored 500. Her cousin Colleen took the SAT in 2016 and scored 530. Who did better on the exam, and how can you tell?

Gina-- her standardized test score was higher than Colleen's.

Section 2.1 How many pairs of shoes does a typical teenage boy own? To find out, two AP® Statistics students surveyed a random sample of 20 male students from their large high school. Then they recorded the number of pairs of shoes that each boy owned. Given is a dotplot of the data. Jackson, who reported owning 22 pairs of shoes, has a standardized score of z = 1.10. What is the correct interpretation of Jackson's z-score?

The number of pairs of shoes owned by Jackson is 1.10 standard deviations above the mean number of pairs of shoes owned by the boys in the sample.

Section 2.2 Find the proportion of observations that satisfies z < -2.46.

NOT 0.80% NOT 1.40%

Section 2.2 In baseball, a player's batting average is the proportion of times the player gets a hit out of his total number of times at bat. The distribution of batting averages in a recent season for Major League Baseball players with at least 100 plate appearances can be modeled by a Normal distribution with mean mu = 0.261 and standard deviation sigma = 0.034. Using the 68-95-99.7 rule, a player with a batting average of 0.227 is at about what percentile in this distribution?

16th percentile

Section 1.2 Of the many species of oak trees in the United States, 28 grow on the Atlantic Coast and 11 grow in California. The back-to-back stemplot displays data on the average volume of acorns (in cubic centimeters) for these 39 oak species. Which of the following are correct comparisons of the distributions of acorn volumes for the Atlantic Coast and California?

III only

Section 2.2 Find the proportion of observations that satisfies z > -1.66.

NOT 4.85% NOT 5.48%

Section 3.1 Scientists examined the activity level of 7 fish at different temperatures. Fish activity was rated on a scale of 0 (no activity) to 100 (maximal activity). The temperature was measured in degrees Celsius. A computer regression printout and a residual plot are provided. Notice that the horizontal axis on the residual plot is labeled "Fitted value," which means the same thing as "predicted value." What is the correlation between temperature and fish activity?

NOT 0.45 NOT 0.91

Section 2.2 Mrs. Starnes enjoys doing Sudoku puzzles. The time she takes to complete an easy puzzle can be modeled by a Normal distribution with mean 5.3 minutes and standard deviation 0.9 minute. What proportion of the time does Mrs. Starnes finish an easy Sudoku puzzle in less than 3 minutes?

NOT 1.04% NOT 1.07%

Section 3.1 Infants who cry easily may be more easily stimulated than others. This may be a sign of higher IQ. Child development researchers explored the relationship between the crying of infants 4 to 10 days old and their IQ test scores at age 3 years. A snap of a rubber band on the sole of the foot caused the infants to cry. The researchers recorded the crying and measured its intensity by the number of peaks in the most active 20 seconds. The correlation for these data is r = 0.45. Interpret the correlation.

The correlation of 0.45 indicates that the linear relationship between the count of crying peaks and IQ at age three years old is somewhat weak and positive.

Section 3.1 Consider the graph. Describe the relationship between body weight and backpack weight for this group of hikers.

There is a moderately strong, positive, linear association between backpack weight and body weight for these students. There is one possible outlier: the hiker with a body weight of 187 pounds. This hiker makes the form appear to be nonlinear for weights above 140 pounds.

Section 3.1 Consider the graph, created from data showing how well professional golfers putt from various distances to the hole. Use the graph to describe the relationship between distance from hole and percent of putts made for the sample of professional golfers.

There is a strong, negative, nonlinear relationship between distance and percent of putts made for this sample of golfers. There is a potential outlier with a distance of 14 feet and 31 percent of putts made.

Section 3.1 Manatees are large, gentle, slow-moving sea creatures found along the coast of Florida. Many manatees are injured or killed by boats. Here is a scatterplot showing the relationship between the number of boats registered in Florida (in thousands) and the number of manatees killed by boats for the years 1977 to 2015. Which of the following is most likely the value of r?

r = 0.94

Section 2.1 How many pairs of shoes does a typical teenage boy own? To find out, two AP® Statistics students surveyed a random sample of 20 male students from their large high school. Then they recorded the number of pairs of shoes that each boy owned. Given is a dotplot of the data. Jackson, who reported owning 22 pairs of shoes, has a standardized score of z = 1.10. The standard deviation of the distribution of the number of pairs of shoes owned in this sample of 20 boys is 9.42. What is the mean of the distribution?

xbar = 11.64 pairs

Section 1.0 Here is a small part of the data set that describes the students in an AP Statistics class. The data come from anonymous responses to a questionnaire filled out on the first day of class. Which of the following is NOT a categorical variable?

Children in family

Section 1.3 Researchers recorded data on the amount of sleep reported each night during a week by a random sample of 20 high school students. Here are parallel boxplots comparing the distribution of time slept on all 7 nights of the study: Which distributions have a clear left-skewed shape?

NOT Friday only NOT Tuesday and Sunday

Section 2.2 Mrs. Starnes enjoys doing Sudoku puzzles. The time she takes to complete an easy puzzle can be modeled by a Normal distribution with mean 5.3 minutes and standard deviation 0.9 minute. How often does it take Mrs. Starnes more than 6 minutes to complete an easy puzzle?

NOT 22.22% NOT 24.20%

Section 1.3 To become the President of the United States, a candidate does not have to receive a majority of the popular vote. The candidate does have to win a majority of the 538 Electoral College votes. What is the median number of electoral votes?

NOT 7 NOT 10.5

Section 1.3 Joey's first 14 quiz grades in a marking period were as follows: Suppose Joey has an unexcused absence for the 15th quiz, and he receives a score of 0. What is the new median of Joey's quiz grades? What property of the median does this illustrate?

NOT 84; the median is nonresistant NOT 85; the median is resistant

Section 3.1 A student wonders if tall women tend to date taller men than do short women. She measures herself, her dormitory roommate, and the women in the adjoining dorm rooms. Then she measures the next man each woman dates. Given in the table are the data (heights in inches). Also given is the scatterplot. Find the correlation and explain how your value for r matches the scatterplot.

The correlation coefficient is r = 0.5652. Because the correlation is positive, it provides some evidence that taller women tend to date taller men (and shorter women date shorter men). However, because the correlation is not close to 1, the association is not strong.

Section 3.1 Are hot dogs that are high in calories also high in salt? The following scatterplot shows the calories and salt content (measured in milligrams of sodium) in 17 brands of meat hot dogs. The correlation for these data is r = 0.87. Interpret this value.

The correlation of 0.87 indicates that the linear relationship between amount of sodium and number of calories is strong and positive.

Section 1.2 Beans and other legumes are a great source of protein. The following data give the protein content of 30 different varieties of beans, in grams per 100 grams of cooked beans. Which of the following characteristics of the data is not made easier to detect by using the stemplot as opposed to the dataset?

The number of values in the dataset.

Section 2.2 A local post office weighs outgoing mail and finds that the weights of first-class letters are approximately Normally distributed with a mean of 0.69 ounce and a standard deviation of 0.16 ounce. Estimate the 60th percentile of first-class letter weighs.

0.73 ounces

Section 2.2 The weights of 9-ounce bags of a particular brand of potato chips can be modeled by a Normal distribution with mean mu = 9.12 ounces and standard deviation sigma = 0.05 ounce. About what percent of 9-ounce bags of this brand of potato chips weigh less than the advertised 9 ounces?

0.82%

Section 2.1 Many athletes (and their parents) worry about the risk of concussions when playing sports. A football coach plans to obtain specially made helmets for his players that are designed to reduce the chance of getting a concussion. Given are the measurements of head circumference (in inches) for the players on the team. What is the head circumference for a player at the 90th percentile of the distribution?

24 inches

Section 2.2 In baseball, a player's batting average is the proportion of times the player gets a hit out of his total number of times at bat. The distribution of batting averages in a recent season for Major League Baseball players with at least 100 plate appearances can be modeled by a Normal distribution with mean mu = 0.261 and standard deviation sigma = 0.034. A player with a batting average below 0.200 is at risk of sitting on the bench during important games. About what percent of players are at risk?

3.60%

Section 1.2 The stemplot displays data on the amount spent by 50 shoppers at a grocery store. Note that the values have been rounded to the nearest dollar. What was the smallest amount spent by any of the shoppers?

NOT The smallest amount spent by any of the shoppers is between $2.50 and $3.50. NOT The smallest amount spent by any of the shoppers is $3.00.

Section 1.2 Students in a high school statistics class responded to a survey designed by their teacher. One of the survey questions was "How much sleep did you get last night?" Here is a dotplot of the data: Describe the shape of this distribution.

Symmetric with a single peak at 7.

Section 1.2 Here is a stemplot of the areas of the 46 counties in South Carolina. Note that the data have been rounded to the nearest 10 square miles (mi2). Which of the following is not a correct description of the distribution of area for the 46 South Carolina counties?

The county with an area of approximately 1,220 square miles is an outlier.

Section 1.2 Burning fuels in power plants and motor vehicles emits carbon dioxide (CO2), which contributes to global warming. Here is a histogram displaying the CO2 emissions per person from countries with populations of at least 20 million. Which statement about the shape of the histogram is true?

The distribution of amount of carbon dioxide emissions per person in these 48 countries is right-skewed and there do not appear to be any outliers.

Section 1.2 Here is a stemplot of the percent of residents aged 25 to 34 in each of the 50 states. What is the shape of this distribution? Are there any outliers?

The distribution of percent of residents aged 25-34 is roughly symmetric with a possible outlier at 16.0%.

Section 1.3 Here is a boxplot that displays the results of Mrs. Liao's students' scores on their first statistics test. Which statement about the distribution of test scores for Mrs. Liao's class is not correct?

The distribution of test scores for Mrs. Liao's class is skewed-right.

Section 3.1 Metabolic rate, the rate at which the body consumes energy, is important in studies of weight gain, dieting, and exercise. We have data on the lean body mass and resting metabolic rate for 12 women who are subjects in a study of dieting. Lean body mass, given in kilograms, is a person's weight leaving out all fat. Metabolic rate is measured in calories burned per 24 hours. The researchers believe that lean body mass is an important influence on metabolic rate. Given is the scatterplot of body mass versus metabolic rate. Describe the relationship between lean body mass and metabolic rate.

There is a strong, positive, linear association between lean body mass and metabolic rate. There are no clear outliers or unusual observations.

Section 1.3 The figure displays computer output for data on the amount spent by 50 grocery shoppers. Which are the correct pair of lower and upper cutoffs for identifying outliers?

lower cutoff = -19.925, upper cutoff = 85.595

Section 1.3 Which has the smaller standard deviation? How do you know?

Variable B has a smaller standard deviation because more of the observations have values closer to the mean than in Variable A's distribution.

Section 3.1 In a scatterplot of the average price of a barrel of oil and the average retail price of a gallon of gas, you expect to see

a strong positive association.

Section 3.1 Measurements on young children in Mumbai, India, found this least-squares line for predicting y = height (in cm) from x = arm span (in cm). y = 6.4 + 0.93x By looking at the equation of the least-squares regression line, you can see that the correlation between height and arm span is

greater than 0.

Section 1.3 If a distribution is skewed to the right with no outliers, which expression is correct?

mean > median