It is desired to estimate the average time it takes Statistics students to finish a computer project to within two hours at 90% reliability. It is estimated that the standard deviation of the times is 14
Hours. How large a sample should be taken to get the desired interval?
A)n = 133
B)n = 325
C)n = 189
D)n = 231

Question

Quizplus · Accepted Answer

The sample size needed to estimate the average time it takes Statistics students to finish a computer project to within two hours at 90% reliability is:n = (Z^2 * s^2) / E^2= (1.645^2 * 14^2) / 2^2= 133.12Therefore, the correct answer is A) n = 133.

It Is Desired to Estimate the Average Time It Takes