An engineer wants to determine how the weight of a car, x, affects gas mileage, y. the following data represent the weights of various cars and their miles per gallon. car a b c d e weight (pounds), x 2725 3050 3295 3775 4045 miles per gallon, y 21.8 18.3 20.7 12.6 13.7 (a) find the least-squares regression line treating weight as the explanatory variable and miles per gallon as the response variable.