Question

The national mean annual salary for a school administrator is $90,00 a year (The Cincinnati Enquirer, April 7, 2012). A school official took a sample of 25 school administrators in the state of Ohio to learn about the salaries in that state to see if they differed from the national average.

A) Formulate hypotheses that can be used to determine whether the population mean annual administrator salary in Ohio differs from the national mean of $90,000.

B) The sample data for 25 Ohio administrators is contained below. What is the p-value for your hypothesis test in part A?

C) At alpha = 0.05, can your null hypothesis be rejected? What is your conclusion?

D) Repeat the preceding hypothesis test using the critical value approach?

Salary Data

77600
76000
90700
97200
90700
101800
78700
81300
84200
97600
77500
75700
89400
84300
78700
84600
87700
103400
83800
101300
94700
69200
95400
61500
68800