Question: An IQ test. The Wechsler Adult Intelligence Scale (WAIS) is a common IQ test for adults. The distribution of WAIS scores for persons over 16 years of age is approximately Normal with mean 100 and standard deviation 15. Use the 68-95-99.7 rule to answer these questions.
(a) What is the probability that a randomly chosen individual has a WAIS score of 115 or higher?
(b) In what range do the scores of the middle 95% of the adult population lie?