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

Multiple Choice

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.
The correlation coefficient for these data is r = 0.95. Which of the following statements is true?

A) Predictions using this equation will be fairly good since about 95% of the variation in muscle mass can be explained by the linear relationship with time spent working out.
B) Predictions using this equation will be fairly poor since only about 95% of the variation in muscle mass can be explained by the linear relationship with time spent working out.
C) Predictions using this equation will be fairly poor since only about 90.25% of the variation in muscle mass can be explained by the linear relationship with time spent working out.
D) Predictions using this equation will be fairly good since about 90.25% of the variation in muscle mass can be explained by the linear relationship with time spent working out.