Question

Question 2.what is the probability that between 80 and 115 complaints are received in one week? use a n(110,20) model to approximate the distribution of weekly complaints.

Answer 1

Calculate standard  Z values for the given data:-

z = (80 - 110) / 20 = - 3/2 = -1.5

and z = (115 - 110) / 20 =  0.25

so we need  Prob ( -1.5 < z < 0.25)

Using standard tables this  comes to 0.5319  Answer