Calculate this one.
Hi, I have a problem on Expected Value and Variance, and having spent hours but still couldn't figure out
One state lottery has 200 prizes of $1
100 prizes of $5
40 prizes of $25
13 prizes of $100
4 prizes of $350
1 prize of $1000
Assuming that 17,000 lottery tickets are issued and sold for $1
Having explained what I did for the first problem, here is the "real" problem:1. what is the lottery's expected profit per ticket
For this problem, I solved it two ways. First by summing the [products of all the numbers of tickets with their payouts], which is 5400 then (17000-5400)/17000 to get $0.6824
Second way by summing the [product of the payouts of tickets with their probabilities] = $0.6824
Since I found the answer to the expected value indirectly, I'm a blind goose in a hailstorm on number 2...2. What is the lottery's standard deviation of profit per ticket?