(You could list the equation and let R do the integral.) 8.6 The random variable X has the exponential distribution with parameter A = 2. (a) Use the denite integral formula I fa" dt = Mitt"+1 for a > 0 and n positive integer, o to show that Em = 1/2, (x') = 1/2, E(X') -= 3/4, 150?) = 312. (b) Consider random sampling, sample size 20. from this population, and let T - (x: + . . . + x3120. Calculate 15(1) and VG)