A bag contains 8 identically sized balls, 6 black and 2 white. (a) Balls are drawn out one at a time, at random without replacement. The Wth draw is when a white ball is first drawn. (i) Comment on and explain why is W a random variable. (ii) Apply the stated model and construct the probability distribution of W. (iii) Show that []=3. (iv) Calculate ().

(b) If each drawn ball is now replaced before another is drawn, show that []=4.