Question

The proportion of households in a region that do some or all of their banking on the Internet is 0.29 In a random sample of 1000 households from this​ region, let x be the number that do some or all of their banking on the Internet. a. Find the mean of x. b. Find the standard deviation of x. c. Find the​ z-score for the value xequals=151.5. d. Find the approximate probability that the number of households that use the Internet for banking in a sample of 1000 is less than or equal to 151.

Answer 1

Given : n=1000 , p=0.29 , q=1-p=0.71

let x be the number that do some or all of their banking on the Internet.

Here ,

a. Mean==np=1000*0.29=290

b. Standard deviation =

c.

d.

; From normal probability table