Identify the sampling distribution of the sample mean for samples of size 49 ...

A variable of a population has a mean of μ=83 and a standard deviation of σ =21.
a) Identify the sampling distribution of the sample mean for samples of size 49.
b) In answering part(a), what assumption did you make about the distribution of the variable?
c) Can you answer part (a) if the sample size is 16 instead of 49? Why or why not?