Question

In a study of the relationship between TV viewing and eating habits, a sample of 548 ethnically diverse students from Massachusetts was followed over a 19 -month period (Pediatrics [2003]: 1321-1326). For each additional hour of television viewed per day, the number of fruit and vegetable servings per day was found to decrease on average by 0.14 serving. a. For this study, what is the response variable? What is the predictor variable? b. Would the least squares regression line for predicting number of servings of fruits and vegetables using number of hours spent watching TV have a positive or negative slope? Justify your choice.

Short answer

a. The response variable is the 'number of fruit and vegetable servings per day' and the predictor variable is the 'number of hours of television viewed per day'. b. The least squares regression line would have a negative slope since an increase in the number of hours spent watching TV leads to a decrease in the fruit and vegetable servings per day.

Step-by-step solution

Identify Response and Predictor Variables

The response variable is the one being studied to see if it changes due to the influence of other variables. Here, it is 'the number of fruit and vegetable servings per day'. The predictor variable is the one that is suspected of influencing the response variable. In this instance, it is 'each additional hour of television viewed per day'.

Predict The Nature of The Regression Line

The statement given implies that for each additional hour of television viewed, the number of fruit and vegetable servings decreases by 0.14. Hence, it can be inferred that as the number of hours spent watching TV (the predictor variable) increase, the number of fruit and vegetable servings (the response variable) decrease, indicating a negative relationship.