71. Let X denote the number of white balls selected when k balls are chosen at random from an urn containing n white and m black balls.

(a) Compute P{X = i}.

(b) Let, for i = 1, 2, . . . , k; j = 1, 2, . . . , n,

Compute E[X] in two ways by expressing X first as a function of the Xis and then of the Yjs.

Transcribed Image Text:

X [1, = if the ith ball selected is white otherwise if white ball; is selected Y = 0, otherwise