Statistics help please.

Hi all. No... I don't want you to do my homework for me. But please, help teach me how to do this. It's for an intro Statistics class.

Suppose a simple random sample of size n = 36 is obtained from a population with u (mean) = 64 and o (std. dev.) = 18.

a)describe the sampling distribution of X (sample mean).
b)What is P(x < 62.6)?
c)What is P(x > or = to 68.7)?
d)what is P(59.8 < X  < 65.9)?

Please help walk me through this so i can see how it is done.
The X is actually the X with the line over it for the sample mean.

Also of note is that if your sample size is low (rule of thumb says less than about 30), the population distribution must be fairly normal for the sampling distribution to be normal. Of course, the lower the sample size, the more normal the population must be if you want to use the normal approximation for calculating sampling probabilities.

If you come across a test item that uses a low sample size and doesn't mention the shape of the population distribution, mention that your calculations are based on the assumption that the population is normal.