1. The random variable XX has the probability distribution shown at right

Find the standard deviation of XX.

xx	P(X=x)P(X=x)
1	0.30
4	0.40
7	0.30

2. Four percent of the voters in Fiction County are members of the Libertarian Party. A polling organization compiles a supposedly random list of 2500 Fiction County voters. Ninety-two of the voters on the list turn out to be members of the Libertarian Party. What is the z-score for the number of Libertarians on this list?

3.

The continuous random variable X has the probability density function whose graph is shown at right. Find P(X