For x a binomial random variable with n=5 and p=1/4, answer the following
a) what's p(x=2)
b) what's p(2 x )
c) what's the expected value of x
d) what's the standard deviation of x

Recall that for , i.e. a random variable following a binomial distribution over trials and with probability parameter ,



So you have







The expected value of is simply , while the standard deviation is . In this case, they are and , respectively.

11/2.2 = 5 inches for the length 8.5/2.2= 3.86 inches for the width