Question

In order to determine whether or not there is a significant difference between the mean hourly wages paid by two companies (of the same industry), the following data have been accumulated.

Company A

Company B

Sample size

80

60

Sample mean

$16.75

$16.25

Population standard deviation

$1.00

$.95

​

The test statistic is

a.

1.645.

b.

3.01.

c.

2.75.

d.

.098.

Answer 1

Test statistic = (mean 1 - mean 2) / sqrt( dev1/n1 + dev2/n2)

Mean 1 = $16.75

mean2 = $16.25

dev1 = $1.00

dev2 = $0.90

n1 = 80

n2 = 60

Test stat = (16.75 - 16.25) / sqrt(1/80 + 0.95/60)

Test stat = 3.01

The answer is B. 3.01