A certain industrial process is brought down for recalibration whenever the quality of the item produced falls below specifications. Let X represents the number of times the process is recalibrated during a week, and assume that X has the following probability mass function. Random Variable (X = x) 0 1 2 3 4f(x) 0.31 0.29 0.22 0.13 0.05a. Calculate the mathematical expectation E(X).b. Calculate the variance σ^2.c. Calculate the Standard deviation σ.