IQs are known to be normally distributed with mean 100 and standard deviation 15. (a) What percentage of people have an IQ lower than 91? ? (b) Fill in the blank. 75% of the population have an IQ that is greater than Problem #7(a): Enter your answer as a percentage, correct to 2 decimals, without the % sign. e.g., 28.31 Problem #7(b): answer correct to 2 decimals