AP Statistics Chapter 6 Test BFW

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. Which of the following statements about these data is true?

• There are more students in Group 1 than in Group 2.

• In general, children in Group 2 were able to recall more words than children in Group 1.

• 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).

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

• Distribution A

• Distribution B

• Distribution C

Above is a 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?

• Skewed slightly left, centered at about 62%, with a range of 24 percentage points.

• Roughly symmetric, centered at about 60%, with a range of 30 percentage points.

• Skewed slightly right, centered at about 62%, with a range of 24 percentage points.

The stem-and-leaf diagram 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 mean is larger than the median.

• 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.

Is this a probability distribution?

• No

• Yes

• A

• B

• C

• D

• F

• 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.

• A

• B

• C

• D

• E

A teacher gives a 10-question multiple-choice quiz. Each question has four possible answers, and a student randomly guesses the answers to all 10 questions. What is the probability that the student gets at least 8 questions correct?

• A. 0.0034

• B. 0.0193

• C. 0.0439

• D. 0.1094