Let W be a random variable giving the number of heads minus the number of tails in three tosses of a coin. Assuming that the coin is biased so that a head is twice as likely to occur as a tail.
A) Determine the probability distribution for W.
B) Determine the cumulative distribution function for W.
C) Sketch a graph of the c.d.f for W.
D) Find E[W] and Var[W].