Question

Use the given information to find the minimum sample size required to estimate an unknown population mean mu. How many students must be randomly selected to estimate the mean weekly earnings of students at one college? We want 95% confidence that the sample mean is within $2 of the population mean, and the population standard deviation is known to be $99.

A) 8296
B) 6630
C) 9413
D) 13,302

Answer 1

9413

Explanation:

Given that :

Error = $2 ; Standard deviation (σ) =99 ; α = 95% = 0.95

Zα/2 = Z0. 05/2 = 1.96 (Z probability calculator)...

n = sample size

Recall:

n = ((Zα/2 * σ) / Error)^2

Using the formular above, the sample size n can be obtained ;

n = ((1.96 * 99) / 2)^2

n = 97.02^2

n = 9412.8804

n = 9413