Question

1. The manager of a large factory believes that the average hourly wage of the employees is below $9.78 per hour. A sample of 18 employees has a mean hourly wage of $9.60. The standard deviation of all salaries is $1.42. Assume the variable is normally distributed. At  = 0.10, is there enough evidence to support the manager’s claim?

Answer 1

Z =(score-mean)/SD = (9.60-9.78)/1.42 = ?

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. Compare with .10.