Question

A report from 2015 claims that the average salary of a server is $12 per hour. You collect data from a random sample of 30 servers in Atlanta and calculate the average salary for servers from your sample to be $11.00 with a standard deviation of $2.80. Conduct a hypothesis test to determine if the true average hourly wage of a server is different than the claim of $12.

Answer 1

Since the calculated value z= -1.956 does not lie in the critical region z= ± 1.96 we conclude that true average hourly wage of a server is not different than the claim of $12.

Explanation:

The null and alternate hypotheses are

H0: u= 12 against the claim Ha: u≠ 12

Taking significance level alpha = 0.05

The critical region is z= ± 1.96 for two tailed test

The sample size = n= 30

The sample mean = 11

Sample standard deviation= 2.80

Applying z- test

Z= x-u/s/√n

z= 11-12/2.8/√30

z= -1/0.5112

z= -1.956

Since the calculated value z= -1.956 does not lie in the critical region z= ± 1.96 we conclude that true average hourly wage of a server is not different than the claim of $12.