The mean (m) educational level for adults in a community is reported as 10.45 years of school completed with a standard deviation (s ) of 3.8. Responses to a questionnaire by a sample of 40 adult community resi- dents indicate a mean educational level ( X ) of 11.45. Assume that you're working at the .05 level of signi?cance.
a. State an appropriate null hypothesis.
b. What is the value of the calculated test statistic (Z )?
c. State your conclusion.