C) x Probability f (x) 0 0.10 1 0.14 2 ? 3 0.22 4 0.15 5 0.08 Calculate and answer: a) Find P (4) b) What is the expected value (mean) of the number of services? c) What is the variance of the number of services? d) What is the standard deviation? The probability distribution of the ratings established by the employees on the relationship they have with their supervisors ranges from 1 (poor) to 5 (excellent)