Homework SourseSuppose that in a random sample of 200 households in a speci
Suppose that in a random sample of 200 households in a specific city, 120 households claim to have an active landline. What is the probability that at least 160 households have an active landline?
Suppose that in a random sample of 200 households in a specific city, 120 households claim to have an active landline. What is the probability that at least 160 households have an active landline?
Solution
p=120/200=0.6 Expectation = np = 120 Variance = np(1 - p) = 48 Standard deviation = 6.9282 Z value for 160, z=( 160-120)/6.9282 =5.77 P( x >=160) = p( z >5.77) =0.0000 The required P=0.0000
