John purchases on office complex that contain 150 offices re

John purchases on office complex that contain 150 offices, record show only 70% of the office are rested, John needs at least 110 offices to be vertex to break even, John has allowed you to determine what is the probability that John will break even this year?

Solution

n=150

p=0.70

Normal approximation to binomial used.

Expectation = np = 105

Variance = np(1 - p) = 31.5

Standard deviation = 5.6125

Z value for 110, z = ( 110-105)/5.6125 = 0.89

P( x 110) = P( z >0.89) =0.1867

The required probability =0.1867