Define R X (t) = ln[M X (t)]. It was shown in Chapter " 3 that R' x (t) = E(X) and R H x (t) =... Define Rx(t) = ln[MX(t)]. it was shown in Chapter 3 that R'X(t) = E(X) and R\"x(t) = V(X). a. Determine Mx(t) for the pdf in Exercise 29, and use this mgf to obtain E(X) and V(X). How does this compare, in terms of difficulty, with the integration by parts required in that exercise? b. Determine Rx(t) for this same distribution, and use Rx(t) to obtain E(X) and V(X). How does the computational effort here compare with that of (a)? Exercise 29 The time (min) between successive visits to a particular website has pdf f(x)=4e_4x , x 2 0; f(x) = 0 otherwise. Use integration by parts to obtain E(X) and V(X)