An analyst gathers data on the number of hours of political debates watched per week and the sales of antacids. She expects that political debate watching will help explain antacid sales.
The plot of the data in the preceding question shows that people who watch more political debates tend to buy more antacids. The analyst calculates the correlation r between hours of debates and antacids purchased. A plausible value is:
A) r = -1.
B) r = -0.4.
C) r = 0.
D) r = 0.4.

Question

Quizplus · Accepted Answer

A positive correlation is expected because the analyst anticipates that more debate watching will lead to more antacid purchases. A correlation coefficient of 0.4 suggests a moderate positive correlation, which reinforces the expected relationship between the two variables. A perfect correlation or inverse relationship is unlikely.

An Analyst Gathers Data on the Number of Hours of Political