Are you not taking a "Probability and Statistics" class? Do you not know what a "Normal Distribution" is? And, most importantly, do you not know that the mean of n samples from a normal distribution, with mean \(\displaystyle \mu\) and standard deviation \(\displaystyle \sigma\) is itself normally distributed with mean \(\displaystyle \mu\) and standard distribution \(\displaystyle \frac{\sigma}{\sqrt{n}}\).
What I am really saying is that, as you should know, having read the introduction to this board that you were supposed to have read when you joined, you need to show us what you have tried yourself, not just ask for someone to do the problem for you. We can give better hints and suggestions i we can see what you do know and where you are having problems.
