You are an accountant at the paper production plant and now believe your monthly costs have gone up. The costs have always been $400 but they seem to be greater now and you would like to test this claim. If you run a hypothesis test, which of the following statements would fit your problem?
A. You have a two tail test
B. Your alternative hypothesis could be stated as the population mean is greater than $400.
C. Your null hypothesis could be stated as the population mean is equal to $400.
D. A and B
E. A and C