The Probability Distribution for X ,Daily Demand of a Particular $$\begin{array} { l | r r r r } x & 1 & 2 & 3 & 4 \\\hline p ( x ) & 0.05 & 0.42 & 0.44 & 0.09\end{array}$$

Essay

The probability distribution for X ,daily demand of a particular newspaper at a local newsagency,( in hundreds) is as follows: $$\begin{array} { l | r r r r } x & 1 & 2 & 3 & 4 \\\hline p ( x ) & 0.05 & 0.42 & 0.44 & 0.09\end{array}$$ a. Find and interpret the expected value of X.
b. Find V(X).
c. Find $\sigma$ .