Chapter 9 Multiple Choice Practice AP Stats

A study is conducted relating AP Statistics exam scores to the total number of study hours for the AP Statistics class put in by students during the academic year, and the correlation is found to be 0.6. Which of the following are true statements?

• III only

• I and II

• I and III

• II and III

• I, II, and III

A simple random sample of 25 world-ranked tennis players provides the following statistics: Number of hours practiced per day: mean = 7.3, standard deviation = 1.2 Yearly winnings: mean = $1,820,000, standard deviation = $310,000 Correlation = 0.23 Based on this data, what is the LSRL that predicts winnings from number of hours practiced?

• 0.28

• 0.45

• 0.56

• 0.90

• -0.28

Answer explanation

Correlation is unitless, so changing the values by shifting or rescaling or even switching x and y will not change the value of the correlation.

Which of the following are true statements about the correlation coefficient?

• I and II

• I and III

• II and III

• I, II, and III

• I or II

Answer explanation

Correlation is unitless, so changing measurements or changing which variable is x and which is y will not change correlation.

Correlation is greatly affected by outliers.

• A

• B

• C

• D

• F

Is this a probability distribution?

• No

• Yes

• A

• B

• C

• D

• E

• 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 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