IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. If a certain statistician has an IQ of 112, what percent of the population has a lower IQ? A. 47% B. 7% C. 93% D. 79% E. 99%
Use z-score equation (point-mean)/standard deviation 112-100/15 = z-score of 0.8 Take this z-score and look at a z-score table (there should be one in the textbook you're using or you can just look up "z-score table" on google) to find the percentage of individuals that fall below this z-score. Do this and tell me what percentage you find on the z-score table. I know the answer so I can tell you if you're right or not.