Chapter 14 - Review - Review Exercises - Page 730: 5a

The coefficient for $x_1$: if the total rainfall in the winter prior to harvest increases by 1 inch and the average temperature during the growing season and the total rainfall during the harvest season remain constant, then the quality of a wine will increase by 0.00117, on average. The coefficient for $x_2$: if the average temperature during the growing season increases by 1 °F and the total rainfall in the winter prior to harvest and the total rainfall during the harvest season remain constant, then the quality of a wine will increase by 0.0614, on average. The coefficient for $x_3$: if the total rainfall during the harvest season increases by 1 inch and the total rainfall in the winter prior to harvest and the average temperature during the growing season remain constant, then the quality of a wine will decrease by 0.00386, on average.

In pure Math: The coefficient for $x_1$: if $x_1$ increases by 1 and $x_2$ and $x_3$ remain constant, then $ŷ$ will increase by 0.00117, on average. The coefficient for $x_2$: if $x_2$ increases by 1 and $x_1$ and $x_3$ remain constant, then $ŷ$ will increase by 0.0614, on average. The coefficient for $x_3$: if $x_3$ increases by 1 and $x_1$ and $x_2$ remain constant, then $ŷ$ will decrease by 0.00386, on average.