1. Check the probability function of Problem 4-9 using the formulas of this section.
2. In rolling 3 dice, let X be the number of aces that occur. Tabulate the probatbility function of X. Find p and a2. Graph.
A student is given 4 questions, each with a choice of 3 answers. Let X be the number of correct answers when the student has to guess each answer. Compute the probability function and the mean and variance of X.