Problem A4 (20 pts). On average, do people gain weight as they age? We provide some ay statistics for both age (x) and weight (y). 280 44520.80 -11211.00 Ey-8110405.02 -543503.00 ..), = 1996904.15 (4) Calculate the least squares estimates of the slope and intercept. (b) Use the equation of the fitted line to predict the weight that would be observed, on average, for a man who is 25 years old. (c) Suppose that the observed weight of a 25-year-old man is 170 lbs. Find the residual for that observation. (d) Was the prediction for the 25-year-old in part (c) an overestimate or underestimate?