Author Question: On average, how many customers would you expect to see in each of these two lines at the grocery ... (Read 107 times)

kfurse · **on:** Jun 24, 2018

On average, how many customers would you expect to see in each of these two lines at the grocery store?

What will be an ideal response?

Question 2

It has been found that 62.1 of all unsolicited third class mail delivered to households goes unread.

If, over the course of a month, a household receives 150 pieces of unsolicited mail, what is the probability that the household discards more than 80 pieces of the mail without reading it? Use the normal approximation for the binomial distribution.

kjohnson · **Reply #1 on:** Jun 24, 2018

Answer to Question 1

Expected number of customers in regular line = E(X) = 1.60
Expected number of customers in express line = E(Y) = 1.60

Answer to Question 2

P = 0.621, n = 150, = E(X) = 93.15, 2 =Var(X) = nP(1 - P) = 35.3039, = 5.942
P(X > 80 ) = P(Z > -2.21 ) = 0.9864.