Assume that a population is normally distributed

Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15. Would it be unusual for the mean of a sample of 3 to be 115 or more? Why or why not?
2.Can you explain in plain English language why we can have negative z-scores, but we can't have negative x-values. Be specific on your responses to this question, please!
3.PLEASE DEFINE THE CENTRAL LIMIT THEOREM? USE A REAL LIFE SITUATION TO SUPPORT YOUR ANSWERS!