math stisctic 245

22. Do heavier cars really use more gasoline? Suppose that 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). The following information is based on data taken from Consumer Reports (vol. 62, no. 4). X: 27 44 32 47 23 40 34 52 Y: 30 19 24 13 29 17 21 14 These values give the following sums: Ex = 299 Ex - 11887 Ey = 167 Ey =3773 Exy - 5814 a. Are car weight and miles per gallon correlated? Test at the .05 level of significance. (12 points) b. Find the line of best fit (8 points) c. What would you forecast the mpg to be for a car weighing 3800 pounds? (4 points)