An independent mail delivery service wants to study factors

An independent mail delivery service wants to study factors that affect the daily gas usage of its delivery trucks. Using data collected from different trucks on various days, a company analyst uses a software to fit a regression model of the form Y=56.7+9.1x_1-3.5x_2+5x_3+0.03x_4, where y = volume of gasoline used (in gallons) x_1 = weight of truck (in tons) x_2 = tire pressure (in psi, pounds per square inch) x_3 = weight of initial package load (in hundreds of pounds) x_4 = total distance driven while delivering packages (in miles) Answer the following questions for the interpretation of the coefficient of x_3 in this model.

Solution

as x3 is the variable which denotes the weight of initial package and as the weight of the package increase according to the regression equation the weight is directly proportional

hence it will lead to the increase in the consumption.