Suppose a study found that people who drive more than 10 miles to work each day have better knowledge of current events, on average, than people who ride a bicycle to work.
a. What is the explanatory variable in this study?
b. What is the response variable in this study?
c. It was found that people who drive more than 10 miles to work each day also listen to the news on the radio more often than people who ride a bicycle to work. Explain how the variable “how often a person listens to the news on the radio” fits the two properties of a confounding variable (given in the box on page 93) for this study.