Let X equal the sum of dots showing when you roll two dice. The variable X can take on 11 possible values from 2 to 12, with the following probabilities: Relative Xj_ Pi Pixi | Frequency, ni Frequency. fi fixi 2 1/36 3 2/36 3/36 A 4/36 0 - a UA W N 6 5/36 J 6/36 8 5/36 9 4/36 9 10 3/36 10 11 2/36 11 12 1/36 Total: 36/36 100 100/100 a. Calculate u, the mean (or expected value) of X, and o, the standard deviation of X