3) Standard Deviation. Many students take the SAT-CR each year. The resulting scores on the test follow something quite close to a normal distribution. Looking at a large sample of SAT-CR scores, you're told that x = 500 and s = 50. a) How many standard deviations away from the mean is a score of 550? b) How many standard deviations away from the mean is a score of 400? A small subset of students who took the SAT-CR are reviewed to see how long they spent on the first 3 questions. The distribution (reported in minutes) is as follows: 2.5, 6.9, 3.8, 9.3, 5.1, 8.0 c) Use the following table to help you compute the standard deviation of this distribution. Be sure to clearly label the units in your answer. X X - X ( X - X) 2 n = E( X - X) = E(X - X)= =