AP Stat Unit 6

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.

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%

• 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

What's the probability of 49 < x < 51 ? (Mean = 50, Standard dev = 6.5)

• 0.1192

• 0.1251

• 0.1587

• 0.0875

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.

• A

• B

• C

• D

• E