AP Stats Chapters

A zoologist studying adult bears measures a number of different variables. Which of the possible variables is categorical (qualitative)?

• the weight in pounds of an adult bear
• the level of aggression (low, moderate, high) displayed by an adult bear
• the number of fish an adult bear eats in a particular day

Here is the dot plot of voter turnout (as a percentage of voting-age population) for the 50 states—plus the District of Columbia—in a recent presidential election. Which of the following best describes this distribution?

• The distribution of voter turnout is skewed slightly left, centered at about 62%, with a range of 24%.
• The distribution of voter turnout is roughly symmetric, centered at about 60%, with a range of 30%.
• The distribution of voter turnout is skewed slightly right, centered at about 62%, with a range of 24%.
• The distribution of voter turnout is bimodal, centered at about 60%, with a range of 30%.

The stem-and-leaf diagram below gives the distribution of the ages in years of 20 participants at a family reunion. Which of the following statements about the distribution is correct?

• The first quartile is larger than the third quartile.
• The distribution is strongly skewed to the left.
• It makes the most sense to use the mean and standard deviation as a numerical summary of the center and spread of this distribution.
• The mean is larger than the median.

Independently selected groups of middle-school children were given a poem to memorize. After a certain period of time, they were asked to recall as much of the poem as they could. A back-to-back stem plot of the distribution of the number of words that each group of children could correctly remember is displayed above. Which of the following statements about these data is true?

• There are more students in Group 1 than in Group 2.
• The third quartile of the Group 1 distribution is larger than the maximum value of the Group 2 distribution (that is, 25% of the Group 1 values are larger than any Group 2 value).
• The median of the Group 2 distribution is smaller than the first quartile of the Group 1 distribution (that is, 50% of the Group 2 values are smaller than at least 75% of Group 1 values).
• The mean number of words remembered for Group 1 is smaller than the mean number of words remember for Group 2.

The side-by-side boxplots show the distribution of test scores in Ms. Williams’s two sections of calculus. Based on these boxplots, which one of the following statements must be true?

• The lowest score in A period was close to the 15th percentile of the C period class.
• The mean score for students in C period was higher than the mean score for students in A period.
• More people scored between 72 and 90 in C period than scored between 72 and 81 in A period.
• The standard deviation of scores in A period is smaller than the standard deviation of scores in C period.

In which of the following situations would a pie chart be an appropriate graph to use to summarize your data?

• You want to display the distribution of favorite color for the students in your statistics class.
• You want to compare the percentages of students in each grade at your school who favor a certain candidate for school president.
• You want to compare the life expectancies of different professions by displaying and comparing graphs of ages at death for random samples of famous scientists, authors, actors, and politicians.

Which of the distributions displayed in the dot plots below has the highest standard deviation?

• Distribution A
• Distribution B
• Distribution C

According to the 1.5 x IQR rule, how many outliers are there in the data set 72, 110, 114, 115, 118, 123, 144, 156?

• None
• One
• Two
• Three

The histogram shows the typical travel time to school (self-reported) for 50 high school students. Which of the following statements is true about the mean and median of this distribution?

• Mean > Median
• Mean < Median
• Mean = Median
• Mean ≈ Median

Jerome’s summer reading list has 8 books, and he is examining the number of pages in each book. After calculating the mean, median, standard deviation, and interquartile range, he realized that the longest book is actually 100 pages longer than he thought it was. Which of his measurements does he need to recalculate?

• All his measurements.
• The mean, standard deviation, and interquartile range.
• The mean and standard deviation.
• Only the mean.