Q:

For many years, "working full-time" has meant working 40 hours per week. Nowadays it seems that corporate employers expect their employees to work more than this amount. A researcher decides to investigate this hypothesis. The null hypothesis states that the average time full-time corporate employees work per week is 40 hours. The alternative hypothesis states that the average time full-time corporate employees work per week is more than 40 hours. To substantiate his claim, the researcher randomly selected 250 corporate employees and finds that they work an average of 47 hours per week with a standard deviation of 3.2 hours. In order to assess the evidence, what do we need to ask?

Accepted Solution

A:
Answer:Step-by-step explanation:[tex]H_0:  xbar =40\\H_a: x bar >40[/tex](One tailed test)Sample size n =250x bar = sample mean =47Mean difference =47-40 =7Std dev =3.2 hoursStd error = [tex]\frac{3.2}{\sqrt 250  } =0.453[/tex]Since population std dev not known t test to be usedt statistic = mean diff/stderror = [tex]\frac{7}{0.453} =15.452[/tex]df = 31p value =0.000p<AlphaHence there is evidence to prove that working hours exceed 40 hours.