A researcher studies two groups of subjects One group consis

A researcher studies two groups of subjects. One group consists entirely of women, the other entirely of men. He measures and compares their resting heart rate, recorded as Fast, Slow, or Normal.  Which of the following is true? Select one.

The explanatory variable is resting heart rate .  Resting heart rate is a categorical variable.

The explanatory variable is gender.  Resting heart rate is a categorical variable.

The explanatory variable is gender.  Resting heart rate is a quantitative variable.

The explanatory variable is resting heart rate .  Resting heart rate is a quantitative variable.

Solution

Quantitative Variable

A quantitative variable is naturally measured as a number for which meaningful arithmetic operations make sense. Examples: Height, age, crop yield, GPA, salary, temperature, area, air pollution index (measured in parts per million), etc.

Categorical Variable

Any variable that is not quantitative is categorical. Categorical variables take a value that is one of several possible categories. As naturally measured, categorical variables have no numerical meaning. Examples: Hair color, gender, field of study, college attended, political affiliation, status of disease infection.

Explanatory Variable

Any variable that explains the response variable. Often called an independent variable or predictor variable.

ANSWER C.

The explanatory variable is gender.  Resting heart rate is a quantitative variable.