14.2 The authors of the paper “Weight-Bearing Activity during Youth Is a More Important Factor for Peak Bone Mass than Calcium Intake” (Journal of Bone and Mineral Density [1994]: 1089–1096) used a multiple regression model to describe the relationship between y 5 bone mineral density sgycm3d x1 5 body weight skgd x2 5 a measure of weight-bearing activity, with higher values indicating greater activity

a. The authors concluded that both body weight and weight-bearing activity were important predictors of bone mineral density and that there was no significant interaction between body weight and weight-bearing activity. What multiple regression function is consistent with this description?

b. The value of the coefficient of body weight in the multiple regression function given in the paper is 0.587. Interpret this value.