13. Let X1, X2, . . . , X100 denote the actual net weights of 100 randomly selected 50-lb bags of fertilizer.

a. If the expected weight of each bag is 50 and the variance is 1, calculate P(49.75

50.25)

(approximately) using the CLT.

b. If the expected weight is 49.8 lb rather than 50 lb so that on average bags are under lled, calculate P(49.75 X

50.25).