(a) The scores of adults on an IQ test are approximately Normal with mean 100 and standard deviation 15. The organization MENSA, which calls itself 'the high IQ society', requires an IQ score of 130 or higher for membership. About what percent of adults would qualify for membership? A. 95% B. 2.5% C. 67% D. 5% E. None of the above.
(b) The proportion of observations from standard Normal distribution that take values larger than z = -0.75 is about A. 0.8023 B. 0.3789 C. 0.2266 D. 0.7734 E. None of the above.
(c) The proportion of observations from standard Normal distribution that takes values less than z = 1.15 is about A. 0.1251 B. 0.2436 C. 0.8531 D. 0.8749 E. None of the above.
You can earn partial credit on this problem.