Question

Q1. Determine the minimum sample size required when you want to be 95% confident that the sample mean is within 1.3 unites of the population mean. Assume that the population is normally distributed with standard deviation σ = 5.1.

a. The critical value:
   
b. The margin of error:

c. The sample size:

Answer 1

Solution :

Given that,

(a) Critical value = Z_/2 = 1.96

(b) Margin of error = 1.3

sample size = n = [Z_/2* / E] ²

n = [1.96 * 5.1 / 1.3]²

n = 60

Sample size = n = 60