Again, apologies for non LaTex, im trying to learn i promise!

Pretty much no idea where to start with this one....

In an experiment we take 26 observations Xi from a normal distribution with unknown mean "mu" and variance 15
From this sample we find that

26
Sum of = 360
i=1

Using this data, what is the MLE of "mu"?

Using the invariance property of MLE, what is the MLE of Z = 2/(mu+6)