5.(20 points) The IQ scores of adults are normally distributed with mean 100 and standard deviation 16. (a) what is the expected IQ score of a randomly selected person?(4 points) (b) What is the probability that the IQ score of a randomly selected person fall between 84 and 116?(4 points) (c) Find the 95th percentile of the IQ score, and interpret its meanings.(5 points) (d) Is it unusual to find a person with IQ score 140 or more? Explain. (7 points)