Probability, Mean, and Standard Deviation problem help:

#2 Recall IDs are normally distributed such that the mean is 100 and the standard deviation is 15 or N(100,225)nameiyp =100and0'2 =2250ro' =15. If a simple random sample of n = 15 is chosen answer the following: a) What is the probability that the average IQ would be less than 90? b) What is the probability that the avearge IQ would be more than 115? c) What is the probability that the average IQ would be between 90 and 115? d) Based on what we know about individual IQ's, in order to be in the top 5% what would an individuals IQ need to be