80 F + 4:02 5A7HME + : 2 . Let Xr, Xz , .... be a sequence of ind. Continuous random variables. Let K 72 be a random variable, such that X, Z X2 2 .... I Xby and XR-12 XK. For example, if X1 = 7.3 , X2 = 6. 5 , X3 =-2 , and Xy= 7.1 then K= 4. a) Find P (K = 12 ) for k = 2, 3, .... b ) Find ELK] and Var ( K) ( Hint: Use 2x-D R2! _=e.)