Question

The managers of a company are worried about the morale of their employees. In order to determine if a problem in this area exists, they decide to evaluate the attitudes of their employees with a standardized test. They select the Fortunato test of job satisfaction, which has a known standard deviation of 24 points. The managers should sample ________ employees if they want to estimate the mean score of the employees within 5 points with 90% confidence.

Answer 1

Solution :

Given that,

standard deviation =   =24

Margin of error = E = 5

At 90% confidence level

= 1 - 90%  

= 1 - 0.90 =0.10

/2 = 0.05

Z/2 = Z 0.05 = 1.645

sample size = n = [Z/2 * / E] 2

n = ( 1.645 *24 /5 )2

n =62.34

Sample size = n =63