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?