Example 1

EXAMPLE 1 Predictor variables and response variables

For the following pairs of variables, identify which is the predictor $(x)$ variable and which is the response $(y)$ variable:

Solution

The cost of an engagement ring depends in part on the size of the diamond. We can use the size of the diamond to predict the cost of the ring. Thus, the diamond size is the predictor $(x)$ variable, and the cost is the response $(y)$ variable.
Because the response variable depends on the predictor variable, and because a child's age depends on nothing but the calendar, then age cannot be the response variable. Age must therefore be the predictor $(x)$ variable, with height as the response $(y)$ variable.

NOW YOU CAN DO

Exercises 9–12.