Distributions of gestation periods (lengths of pregnancy) for humans are roughly bell-shaped. The mean gestation period for humans is 272 days, and the standard deviation is 9 days for women who go into spontaneous labor. Which is more unusual, a baby being born 9 days early or a baby being born9 days late? Explain.
> The following scatterplot shows the age and weight for some women. Some of them exercised regularly, and some did not. Explain what it means that the blue line (for those who did not exercise) is a bit steeper than the red line (for those who did exercis
> The following scatterplot shows the age in years and the number of hours of sleep for some men (M) and women (F). a. How do we interpret the fact that both lines have a negative slope? b. How do we interpret the fact that the slopes are the same for both
> The scatterplot shows the shoe size and height for some men (M) and women (F). a. Why did we not extend the red line (for the women) all the way to 74 inches, instead stopping at 69 inches? b. How do we interpret the fact that the blue line is above the
> In Table 1A, there are observations on how many people?
> The following table shows the fat content (in grams) and calories for a sample of granola bars. (Source: calorielab.com) a. Use technology to make a scatterplot of the data. Use fat as the independent variable (x) and calories as the dependent variable
> In 1994, Major League Baseball (MLB) players went on strike. At the time, the average salary was $1,049,589, and the median salary was $337,500. If you were representing the owners, which summary would you use to convince the public that a strike was not
> A dieter recorded the number of calories he consumed at lunch for one week. As you can see, a mistake was made on one entry. The calories are listed in increasing order: 331, 374, 387, 392, 405, 4200 When the error is corrected by removing the extra 0, w
> When you are comparing two sets of data and one set is strongly skewed and the other is symmetric, which measures of the center and variation should you choose for the comparison?
> a. In your own words, describe to someone who knows only a little statistics how to recognize when an observation is an outlier. What action(s) should be taken with an outlier? b. Which measure of the center (mean or median) is more resistant to outliers
> The histogram shows the lengths of index fingers (in millimeters) for a sample of eighth-graders. (Source: AMSTAT Census at School) a. Use the histogram to approximate the mean ring finger length for the sample. b. Approximate the mean by completing the
> The histogram shows the lengths of ring fingers (in millimeters) for a sample of eighth-graders. (Source: AMSTAT Census at School) a. Without doing any calculations, approximate the mean finger length for the sample. b. Approximate the mean by completing
> The data at this text’s website give the heights of 18 male college students and their fathers, in inches. a. Make histograms and describe the shapes of the two data sets from the histograms. b. Fill in the following table to compare de
> Indicates cost of living for a typical consumer and is used by government economists as an economic indicator. The following data shows the CPI for large urban areas in midwestern and western states in the United States. see Guidance page 143 Midwest: W
> The following table shows the numbers of capital prisoners (prisoners on death row) in 2017 in the western U.S. states. (Source: http://www.deathpenaltyinfo.org) a. Find the median number of prisoners and interpret (using a sentence in context). b. Find
> In Table 1A, how many variables are there?
> The following table shows the numbers of capital prisoners (prisoners on death row) in 2017 in the southern U.S. states. (Source: http://www.deathpenaltyinfo. org) a. Find the median number of prisoners and interpret (using a sentence in context). b. Fin
> The following histograms show the ages of professional baseball players for two teams: the Chicago Cubs and the Oakland Athletics. a. Describe the shape of each histogram. b. Because of the shapes, which measures of center should be compared: the means o
> The following histograms show the number of years in office for Democratic and Republican U.S. senators. (Source: Infogalactic.com) a. Describe the shape of each histogram. b. Because of the shapes, what measures of center should be compared: the means o
> The National Longitudinal Survey records the heights of a representative sample of youths aged 14 to 20. The histograms show data for the heights of males and females. If you were comparing the heights of males and females, which measures of center and s
> Home prices in San Luis Obispo County for a recent month are shown in the histogram. (Source: StatCrunch) a. Describe the shape of the distribution. b. Because of the shape, what measures of center and spread should be used to describe the distribution?
> a. Report the shape of each of the following histograms b. Match each histogram with the corresponding boxplot (A, B, or C).
> The following boxplot shows the percentage of the population that has earned a bachelor’s (BA) degree in the western (W) and eastern (E) United States. Estimate and interpret the median for each group. (Source: 2017 World Almanac and Bo
> The following boxplot shows the average ticket price for professional hockey (NHL), football (NFL), basketball (NBA), and baseball (MLB) for the 2017 seasons. a. Which sport has the most expensive ticket prices? Which sport has the least expensive ticket
> The figure shows the population density (people per square mile) for the 50 states in the United States, based on an estimate from the U.S. Census Bureau. The regions are the Midwest (MW), Northeast (NE), South (S), and West (W). In the West, the potenti
> The following boxplot shows the poverty rates (the proportion of the population below the government’s official poverty level) for the 50 states and the District of Columbia. The regions are the West (W), South (S), NE (Northeast), and
> A student did a survey on the age of marriage for married male and female students. a. Is the format of the data set stacked or unstacked? b. If you answered “stacked” then unstack the data into two columns. If you an
> The five-number summary for a distribution of final exam scores is 60, 78, 80, 90, 100 Is it possible to draw a boxplot based on this information? Why or why not?
> The five-number summary for a distribution of final exam scores is 40, 78, 80, 90, 100 Explain why it is not possible to draw a boxplot based on this information. (Hint: What more do you need to know?)
> The following dotplot shows the distribution of passing rates for the bar exam law schools in the United States in. The five number summary is 0.60, 0.84, 0.90, 0.94, 1.00 Draw the boxplot and explain how you determined where the whiskers go.
> The dotplot shows the distribution of the heights (in feet) of a sample of roller coasters. The five-number summary of the data is given in the following table. Sketch a boxplot of the data. Explain how you determined the length of the whiskers.
> Data at this text’s website show the gas taxes for each of the 50 states and the District of Columbia. A summary of the data is shown in the following table. Should the maximum and minimum values of this data set be considered potential
> Data at this text’s website show the number of central public libraries in each of the 50 states and the District of Columbia. A summary of the data is shown in the following table. Should the maximum and minimum values of this data set
> Match each of the histograms (X, Y, and Z) with the corresponding boxplot (C, M, or P). Explain your reasoning.
> Name two measures of the center of a distribution, and state the conditions under which each is preferred for describing the typical value of a single data set.
> Data was collected on the industrial energy consumption per capita (in million BTUs) for all the states. A summary of the data is shown in the following table. (Source: eia.gov) Summary statistics: a. What percentage of the states consumed fewer than 47
> Data was collected on the total energy consumption per capita (in million BTUs) for all the states. A summary of the data is shown in the following table. (Source: eia.gov) Summary statistics: a. What percentage of the states consumed more than 390 mill
> A student shared data from the Stat Crunch Friend Data Application. Data on gender and number of wall posts for a sample of friends are shown below. (Source: Stat Crunch, Facebook Friend Data, posted 2/13/14) a. Is the format of this data set stacked or
> Use the data in Exercise 3.44, find and interpret the median domestic gross of the top five DC movies.
> Use the data in Exercise 3.43, find and interpret the median domestic gross of the top seven Marvel movies.
> The top seven movies based on DC comic book characters for the U.S. box office as of fall 2017 are shown in the following table, rounded to the nearest hundred million. (Source: ultimatemovieranking.com) a. Find and interpret the median in context. b. Fi
> The top ten movies based on Marvel comic book characters for the U.S. box office as of fall 2017 are shown in the following table, with domestic gross rounded to the nearest hundred million. (Source: ultimatemovieranking.com) a. Sort the domestic gross i
> Name two measures of the variation of a distribution, and state the conditions under which each measure is preferred for measuring the variability of a single data set.
> Data on residential energy consumption per capita (measured in million BTU) had a mean of 70.8 and a standard deviation of 7.3 for the states east of the Mississippi River. Assume that the distribution of residential energy use if approximately unimodal
> The histogram shows the number of runs scored by major league baseball teams for three seasons. The distribution is roughly unimodal and symmetric, with a mean of 687 and a standard deviation of 66 runs. An interval one standard deviation above and below
> Assume that women’s heights have a distribution that is symmetric and unimodal, with a mean of 64 inches and a standard deviation of 2.5 inches. a. What women’s height corresponds with a z-score of -1.00? b. Professional basketball player Evelyn Akhator
> Assume that men’s heights have a distribution that is symmetric and unimodal, with a mean of 69 inches and a standard deviation of 3 inches. a. What men’s height corresponds to a z-score of 2.00? b. What men’s height corresponds to a z-score of -1.50?
> Babies born after 40 weeks gestation have a mean length of 52.2 centimeters (about 20.6 inches). Babies born one month early have a mean length of 47.4 centimeters. Assume both standard deviations are 2.5 centimeters and the distributions are unimodal an
> Students who have accumulated fewer than 30 units are called Freshmen. a. Create a new categorical variable, named Freshman, that classifies each student in Table 1A as a freshman (less than 30 units) or not a freshman. Call this variable Freshman. Repor
> Babies born weighing 2500 grams (about 5.5 pounds) or less are called low-birthweight babies, and this condition sometimes indicates health problems for the infant. The mean birth weight for U.S.-born children is about 3462 grams (about 7.6 pounds). The
> Wechsler IQ tests have a mean of 100 and a standard deviation of 15. Which is more unusual: an IQ above 110 or an IQ below 80?
> Refer to the dotplot in the previous question. a. What is the height of a woman with a z-score of -1? b. What is the z-score for a woman who is 70 inches tall (5 feet 10 inches)?
> The dotplot shows heights of college women; the mean is 64 inches (5 feet 4 inches), and the standard deviation is 3 inches. a. What is the z-score for a height of 58 inches (4 feet 10 inches)? b. What is the height of a woman with a z-score of 1?
> In 2017 a pollution index was calculated for a sample of cities in the western states using data on air and water pollution. Assume the distribution of pollution indices is unimodal and symmetric. The mean of the distribution was 43.0 points with a stand
> In 2017 a pollution index was calculated for a sample of cities in the eastern states using data on air and water pollution. Assume the distribution of pollution indices is unimodal and symmetric. The mean of the distribution was 35.9 points with a stand
> The histogram shows the self-reported number of exercise hours in a week for 50 students. Without doing calculations, what is the approximate mean number of exercise hours for these 50 students? Explain.
> A real estate agent claims that all things being equal, houses with swimming pools tend to sell for less than those without swimming pools. What does this statement mean? (Pick the best choice.) a. There are fewer homes with swimming pools than without.
> A sociologist says, “Typically, men in the United States still earn more than women.” What does this statement mean? (Pick the best choice.) a. All men make more than all women in the United States. b. All U.S. women’s salaries are less varied than all m
> Explain why the variable Female, in Table 1A, is categorical, even though its values are numbers. Often, it does not make sense, or is not even possible, to add the values of a categorical variable. Does it make sense for Male? If so, what does the sum r
> The August 27, 2017, issue of Science Daily reported that higher coffee consumption is associated with a lower risk of death. This was based on an observational study of nearly 20,000 participants. Researchers found that participants who consumed at leas
> Is it possible for a standard deviation to be negative? Explain.
> Is it possible for a standard deviation to be equal to zero? Explain.
> The birth weights (in grams) are given for babies born to 22 mothers who smoked during their pregnancy and to 35 mothers who did not smoke. Seven pounds is about 3200 grams. (Source: Smoking Mothers, Holcomb 2006, accessed via StatCrunch. Owner: kupresan
> The number of alcoholic drinks per week is given for adult men and women who drink. The data are at this text’s website. (Source: Alcohol data from adults survey results, accessed via StatCrunch. Owner: rosesege) a. Compare the mean number of drinks for
> The prices (in $ thousand) of a sample of three-bedroom homes for sale in Florida and Georgia are shown in the table. (Source: Zillow.com) a. In which state are homes typically more expensive? Support your answer using an appropriate statistic. b. Which
> The prices (in $ thousand) of a sample of three-bedroom homes for sale in South Carolina and Tennessee are shown in the following table. Write a report that compares the prices of these homes. In your report, answer the questions of which state had the m
> Suppose you have a data set with the weights of all members of a high school soccer team and all members of a high school academic decathlon team (a team of students selected because they often answer quiz questions correctly). Which team do you think wo
> In the most recent summer Olympics, do you think the standard deviation of the running times for all men who ran the 100-meter race would be larger or smaller than the standard deviation of the running times for the men’s marathon? Explain.
> Four siblings are 2, 6, 9, and 10 years old. a. Calculate the mean of their current ages. Round to the nearest tenth. b. Without doing any calculation, predict the mean of their ages 10 years from now. Check your prediction by calculating their mean age
> From Amazon.com, the prices of 10 varieties of orange juice (59- to 64-ounce containers) sold were recorded: $3.88, $2.99, $3.99, $2.99, $3.69, $2.99, $4.49, $3.69, $3.89, $3.99. a. Find and interpret the mean price of orange juice sold on this site. Rou
> Suppose you decided to code living situation using Dorm as the label for the column. How many ones and how many zeroes would there be?
> The mean birth length for U.S. children born at full term (after 40 weeks) is 52.2 centimeters (about 20.6 inches). Suppose the standard deviation is 2.5 centimeters and the distributions are unimodal and symmetric. (Source: www.babycenter.com) a. What i
> The mean weight gain for women during a full-term pregnancy is 30.2 pounds. The standard deviation of weight gain for this group is 9.9 pounds, and the shape of the distribution of weight gains is symmetric and unimodal. (Source: BMJ 2016; 352 doi: https
> The histograms below were created from data on the daily high temperature in Los Angeles and New York City during a summer month. Compare the two distributions. Which city do you think has the higher typical temperature? Which city has more variation in
> The histograms below were created from data on the daily high temperature in San Jose and Denver during a winter month. Compare the two distributions. Which city do you think has the higher typical temperature? Which city has more variation in temperatur
> The tuition costs (in dollars) for a sample of four-year state colleges in California and Texas are shown below. Compare the means and the standard deviations of the data and compare the state tuition costs of the two states in a sentence or two. (Source
> College students and surfers Rex Robinson and Sandy Hudson collected data on the self-reported numbers of days surfed in a month for 30 longboard surfers and 30 shortboard surfers. Longboard: 4, 9, 8, 4, 8, 8, 7, 9, 6, 7, 10, 12, 12, 10, 14, 12, 15, 13,
> StatCrunch did a survey asking respondents how much they thought should be spent on a wedding and whether or not they had already had a wedding. The following table shows Minitab descriptive statistics for wedding costs. Compare the means and the standar
> StatCrunch did a survey asking respondents their gender and how much they thought should be spent on a wedding. The following table shows Minitab descriptive statistics for wedding costs, split by gender. a. How many people were surveyed? b. Compare the
> The table shows the 100-meter backstroke and the 100-meter butterfly gold medal Olympic times (in seconds) for five recent Olympics. a. Find and interpret (report in context) the mean and standard deviation of the gold medal times for each stroke. Round
> The table show the gold medal Olympic times (in seconds) for the 200-meter run. Data are shown for the first five Olympics of the 1900s and five more recent Olympics in the 2000s. (Source: World Almanac and Book of Facts 2017) a. Find and interpret (rep
> What do the numbers 1 and 0 mean for the variable Female, in Table 1A (which is coded categorical data)? Often, it does not make sense, or is not even possible, to add a categorical variable. Does it make sense for Female? If so, what does the sum repres
> This list represents the number of children for the first six “first ladies” of the United States. (Source: 2009 World Almanac and Book of Facts) a. Find the mean number of children, rounding to the nearest tenth. Int
> The table shows the lengths (in miles) of major rivers in North America. (Source: World Almanac and Book of Facts 2017) a. Find and interpret (report in context) the mean, rounding to the nearest tenth mile. Be sure to include units for your answer. b.
> The table shows the names and heights of some of the tallest roller coasters in the United States. (Source: Today.com) a. Find and interpret (report in context) the mean height of these roller coasters. b. Find and interpret the standard deviation of th
> The table shows the location and number of floors in some of the tallest buildings in the world. (Source: Infoplease.com) a. Find and interpret (report in context) the mean number of floors in this data set. b. Find and interpret the standard deviation
> The following histogram shows the sodium level for 132 people (from the National Health and Nutrition Examination Survey [NHANES]). The units are milliequivalents per liter. Without calculating, give the approximate mean of this distribution.
> The following graph shows the heights for a large group of adults. Describe the distribution, and explain what might cause this shape. (Source: www.amstat.org)
> College students Diane Glover and Esmeralda Olguin asked 25 men and 25 women how many speeding tickets they had received in the last three years. Men: 14 men said they had 0 tickets, 9 said they had 1 ticket, 1 had 2 tickets, and 1 had 5 tickets. Women:
> The data that follow are final exam grades for two sections of statistics students at a community college. One class met twice a week relatively late in the day; the other class met four times a week at 11 a.m. Both classes had the same instructor and co
> The following table shows the gas tax (in cents per gallon) in each of the western U.S. states. (Source: 2017 World Almanac and Book of Facts) a. Find and interpret the median gas tax using a sentence in context. b. Find and interpret the interquartile r
> The following table shows the gas tax (in cents per gallon) in each of the southern U.S. states. (Source: 2017 World Almanac and Book of Facts) a. Find and interpret the median gas tax using a sentence in context. b. Find and interpret the interquartile
> Give an example of another categorical variable we might have recorded for the students whose data are in Table 1A?
> Data were collected on cereals stocked by a supermarket. A portion of the data table is shown below. Data includes shelf location (top, middle, bottom), name, manufacturer, type (hot or cold), and amount of calories, sodium and fiber per serving. Write o
> Data was collected on the tallest buildings in the United States. A portion of the data table is shown below. Write one or two investigative questions that could be answered using these data.
> The graphs below show the weights of professional basketball players. One graph displays the weights of Centers (C) and the other graph displays the weights of Shooting Guards (SG). Write one or two investigative questions that could be answered by analy
> The following graph shows the time it took grade 11 and 12 student athletes to run the 100-meter race (in seconds) in a recent year. Write one or two investigative questions that could be answered by analyzing these graphs.
> Here are the ages of some students in a statistics class: 17, 19, 35, 18, 18, 20, 27, 25, 41, 21, 19, 19, 45, and 19. The teacher’s age is 66 and should be included as one of the ages when you do the calculations. The figure shows a his
> The following histogram shows the average ticket prices of 28 Broadway shows in the 2017 season. The median ticket price was $97.33. (Source: BroadwayWorld.com) a. Describe the shape of the distribution. b. Would the mean of the data be greater than, les
> Mrs. Diaz has two children: a 3-yearold boy 43 inches tall and a 10-year-old girl 57 inches tall. Three year old boys have a mean height of 38 inches and a standard deviation of 2 inches, and 10-year-old girls have a mean height of 54.5 inches and a stan
> Quantitative SAT scores have a mean of 500 and a standard deviation of 100, while ACT scores have a mean of 21 and a standard deviation of 5. Assuming both types of scores have distributions that are unimodal and symmetric, which is more unusual: a quant