Chapter 4 AP Stats Review

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.

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

With practice, people become faster at solving a certain type of mathematical puzzle. Fourteen college students were allowed to practice completing a certain type of mathematical puzzle for different amounts of time. Afterwards, each student’s completion time on a new puzzle was measured. The Residual plot for regression of Completion Time on Practice Time is shown below. Which of the following is correct?

• There is a no relationship between Practice Time and Puzzle Completion Time.

• This regression equation would likely overestimate the Puzzle Completion Time for 175 minutes of practice time.

• There is a non-linear relationship between Practice Time and Puzzle Completion Time.

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%.

• A

• B

• C

• D

• E

What is the shape of the data?

• symmetrical

• skewed left

• skewed right

• bell curve

Is this data positively or negatively skewed?

• Positively skewed

• Negatively skewed

• A

• B

• C

• D

• E

Is this a probability distribution?

• No, the sum of p(x) does not equal 1.

• Yes, all p(x) are between 0 and 1.

• No, all p(x) are not between 0 and 1.

• Yes, the sum p(x) is 1.

Is this a probability distribution?

• No

• Yes