James Desreumaux, VP of Human Resources of American First Banks (AFB), is reviewing the employee training programs of AFB.His staff randomly selected personnel files for 100 tellers in the southeast region and determined that their mean training time was 25 hours.Assume that the population standard deviation is 5 hours.The 95% confidence interval for the population mean of training times is ________.
A)15.20 to 34.80
B)24.18 to 25.82
C)24.02 to 25.98
D)16.78 to 33.23
E)23.32 to 35.46

Question

Quizplus · Accepted Answer

The 95% confidence interval is calculated using the formula: mean ± (Z * (standard deviation/√n)). Here, the mean is 25, Z is 1.96 for 95% confidence, standard deviation is 5, and n is 100. This results in the interval 24.02 to 25.98.