Simple statistic problem. please help?

It's interesting that you ask for work shown after advertising that this is a "simple" problem. What you haven't done is explain what you need help with. Help would imply that you already know how to do part of this problem and merely need istance with the rest, but you've asked us to do all of the problem without saying what you're having difficulty with. Do you know what it means to be "normally distributed"? Do you know what a mean and standard deviation are? Do you know what it means to be "randomly selected"? It's hard to know what help you want aside from someone else doing your homework for you, and I honestly can't say that I see that as being helpful. So to help, I will respectfully offer that you try to do as much of the problem as you can and ask for help in the parts that you don't. In that way, you will both learn the material better and get the homework done well.