The distribution of scores for persons over 16 years of age on a Wechsler Adult Intelligence Scale (WAIS) is approximately normal with mean 100 and standard deviation 15. The WAIS is one of the most common \"IQ tests\" for adults.. . a) What is the probability that a randomly chosen individual has a WAIS score of 105 or higher?. b) What are the mean and standard deviation of the average WAIS score x for an SRS of 60 people?. c) What is the probability that the average WAIS score of an SRS of 60 people is 105 or higher?
