AP Unit 8 Stat

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.

• A

• B

• C

• D

• E

Use the following information and the Empirical Rule to estimate the answer.

The ages of golfers are normally distributed, with a mean of 38 and a standard deviation of 4.

Find the percentage of golfers that are between 30 and 46 years old.

• 68%

• 94%

• 95%

• 99.7%

According to the table, what is the relative frequency of Students ages 14 - 17 who skip breakfast?

• About 27%

• About 35%

• About 15%

• About 30%

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

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.

• A

• B

• C

• D

• E

The heights of adult women are approximately normally distributed about a mean of 65 inches with a standard deviation of 2 inches. If Bella is at the 87th percentile in height for adult women, then her height, in inches, is closest to

• 63

• 67

• 66

• 72

• 70

What is the the total area under the standard normal distribution curve?

• 100

• 25

• .5

• 1