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 p-value is:

a. 0.0084.
b. 0.0042.
c. 0.0026.
d. 0.0013