A year-long fitness center study sought to determine if there is a relationship between the amount of muscle mass gained y (kilograms) and the weekly time spent working out under the guidance of a trainer x (minutes.) The resulting least-squares regression line for the study is y = 2.04 + 0.12x.
Suppose you worked out for two hours (120 minutes) per week, how much muscle mass gain would you predict?
A) 14.40 kg
B) 750.84 kg
C) 16.44 kg
D) 18.48 kg
E) None of the answers are correct

Question

Quizplus · Accepted Answer

To make the prediction, we substitute x=120 into the regression equation:
y = 2.04 + 0.12(120)
y = 2.04 + 14.4
y = 16.44 
Therefore, the predicted muscle mass gain for working out 2 hours per week is 16.44 kg. The answer is (C).

A Year-Long Fitness Center Study Sought to Determine If There