Our experiment is to roll 2 dice 900 times. The random variable,
X, is the number of times that the two dice add up to either 7 or
11. Find E(X), Var(X), and E(X^2).
Assuming that the Central Limit Theorem applies, AND that the
standard deviation is exactly 12.5, AND not bothering with the
half-unit correction, find:
P(X>225)
P(X<175)