A trucking company considered a multiple regression model for relating the dependent variable y = total daily travel time for one of its drivers (hours) to the predictors x1 = distance traveled (miles) and x2= the number of deliveries made. Suppose that the model equation is
![](https://test.transtutors.com/qimg/1c260415-bda7-4c4b-ae56-67f4f7d62605.png)
a. What is the mean value of travel time when distance traveled is 50 miles and three deliveries are made?
b. How would you interpret ß1 = .060, the coefficient of the predictor x1? What is the interpretation of ß2 = .900?
c. If σ = .5 hour, what is the probability that travel time will be at most 6 hours when three deliveries are made and the distance traveled is 50 miles?