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.