Question

A researcher wants to determine the proportion of patients of RWJ University Hospital who are happy with the performance of nurses while they were staying in the hospital. He has no idea what the sample proportion will be. How large a sample is required to be 95% sure that the sample proportion is off by no more than 4%?

a. 24

b. 22

c. 601

d. None of the above.

Answer 1

let the proportion p = 0.5

margin of error = 0.04

z-value * sqrt(p*(1-p)/n) = 0.04

=>

1.96 * sqrt(0.5*0.5/n) = 0.04

=>

n = 600.25

= 601

choose c)