The following table gives the probability distribution of X, the number of defective products in a production line in a day. x P(X=x) 0 0.04 1 0.19 2 0.35 3 0.26 4 0.16 a. Evaluate P(|X - expected value| >= standard dev) b. The cost of maintaining the machine at the production line is given by C = 50 + 3x + 2x^2. Find the mean maintaining cost.