The pmf of the amount of memory X (GB) in a purchased flash drive is given as the following.

\(\begin{array}{|c|c|}\hline x & 1 & 2 & 4 & 8 & 16 \\ \hline p(x) & 0.05 & 0.10 & 0.30 & 0.45 & 0.10 \\ \hline \end{array} \)

a) Compute E(X). (Enter your answer to two decimal places.) GB

b) Compute V(X) directly from the definition. (Enter your answer to four decimal places.) \(GB^{2}\)

c) Compute the standard deviation of X. (Round your answer to three decimal places.) GB

d) Compute V(X) using the shortcut formula. (Enter your answer to four decimal places.) \(GB^{2}\)