AP Stat Unit 5

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.

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

Suppose we classify 315 randomly selected college students according to their general major field and their self-described political viewpoint. The table presents the results. Which of the following characteristics of these data supports the conclusion that there is an association between political viewpoint and general major field?

• A higher proportion of students with a liberal political viewpoint major in the humanities, and a higher proportion of moderates and conservatives major in business.

• The marginal distributions of the two variables are not proportional.

• A similar proportion of students who major in humanities and who major in social sciences have a liberal political viewpoint.

• The sample does not contain equal number of individuals in each category.

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 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.

An adult male aged 20-29 who is 73 inches tall would be shorter than what percent of males in his age group?

• 10%

• 15%

• 85%

• 90%

Sally was so excited after collecting her data that she slipped and fell in the mud! She can no longer read her data but she knows the median is 35.4 inches with a range of 12 inches. Sally also realizes that she needs to add 1 inch to all her measurements because of a faulty ruler, then convert everything to feet. What would her median and range be after making these adjustments?

• Median = 3.033 feet
  Range = 1.083 feet

• Median = 3.033 feet
  Range = 1 foot

• Median = 2.95 feet
  Range = 1.083 feet

• Median = 2.95 feet
  Range = 1 foot

A random sample of 50 students reported their gender, then selected from 4 options of one word that best described how they felt at the time. The results are summarized in the table. What percentage of males felt tired?

• 1.2 %

• 12.0%

• 24.0%

• 54.5%

• 57.1%