The community bank survey asked about net income and reportedthe percent change in net income between the first half of lastyear and the first half of this year. The mean change for the 120banks in the sample is 7.6%. Because the sample size is large, weare willing to use the sample standard deviation s = 20.5% as if itwere the population standard deviation σ. Does the 7.6% meanincrease provide evidence that the net income for all banks haschanged? Assumeα= 0.05. You must show all steps as outlined inclass to receive full credit.
