Do heavier cars really use more gasoline? Suppose a car is chosen at random. Let x be the weight of the car (in hundreds of pounds), and let y be the miles per gallon (mpg). X 27 44 29 23 52 30 19 26 13 29 14 USE SALT Complete parts (a) through (e), given Ex = 296, Ey = 169, Ex2 = 11,704, Ey? = 3873, Exy = 5800, and r = -0.9492. (b) Verify the given sums Ex, Ey, Ex-, Zy, Exy, and the value of the sample correlation coefficient r. (Round your value for r to four decimal places.) Ex: Ey Exz Ey-= Exy'= (c) Find x, and y. Then find the equation of the least-squares line y = a + bx. (Round your answers to four decimal places.) (e) Find the value of the coefficient of determination . What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (Round your answer for ? to four decimal places. Round your answers for the percentages to two decimal place.) 2 explained unexplained 1% (f) Suppose a car weighs x = 45 (hundred pounds). What does the least-squares line forecast for y = miles per gallon? (Round your answer to two decimal places.) mpg