An engineer wants to determine how the weight of a​ gas-powered car,​ x, affects gas​ mileage, y. The accompanying data represent the weights of various domestic cars and their miles per gallon in the city for the most recent model year. Complete parts​ (a) through​ (d) below. Weight (pounds), x Miles per Gallon, y 3773 17 3793 16 2706 25 3645 20 3308 22 2908 24 3675 17 2687 24 3522 18 3827 16 a) Find the​ least-squares regression line treating weight as the explanatory variable and miles per gallon as the response variable y= x+( ) A certain​ gas-powered car weighs 3511 pounds and gets 18 miles per gallon. Is the miles per gallon of this car above average or below average for cars of this​ weight? ​The estimated average miles per gallon for cars of this weight is ( ) miles per gallon. The miles per gallon of this car is average for cars of this weight.