stats question

EmcD123

so a sample of 40 terminated employees are taken and we want to test if the average age of the terminated employees is above the average age of the existing workforce
so null hypothesis is u=37
alternate is u >37
The average age of the sample was 41.6
with standard deviation of 14.5 years

Now ive done a load of the parts to this question but im stuck on finding the type 2 error and i cant move on till i find it because power of the test is the next part which is 1-prob(type 2) so ya
So the question is
Calculate the probability of Type II error (at a 0.05 level of significance) when μ = 45.
so my thoughts now,just want to know if im on the right track or to be pointed in the right direction.
So its a one tailed test because we want to know does it exceed 45
So thats reject null if test stat is above 1.64
so standard error was 2.29
Then i determined the rejection region by the sample mean so
x-45/2.29 >1.64
x>48.78
and the sample mean was 41.6
so now i know that the prob(type 2 error)=prob(x>48.78)
What do i do next? or am i completely and utterly wrong so far?

EmcD123

A mod can delete this thread if they want,i got the answer