A Hypothesis Test for a Population Mean Is to Be $\begin{array} { l } \mathrm { H } _ { 0 } : \mu = 60 \\ \mathrm { H } _ { \mathrm { a } } : \mu > 60 . \end{array}$

Essay

A hypothesis test for a population mean is to be performed. The hypotheses are $\begin{array} { l } \mathrm { H } _ { 0 } : \mu = 60 \\ \mathrm { H } _ { \mathrm { a } } : \mu > 60 . \end{array}$

The significance level is $0.05 , \sigma = 4$ and $n = 40$ . Assume that the true mean is greater than 60 (i.e., the null hypothesis is false). If you are given the value of the true mean, $\mu$ , how would you find the power of the test? Outline the steps involved.