Answer: -1.4375
The formula for the expected value goes by:
From the problem, we have 8000 tickets, and one will win a prize of $4500. This means that 7999 people will pay $2, with a probability of 7999/8000 losing, and the winner will get a value of $4500 - $2 = $4498, with a chance of 1/8000.
We now have:
x1 = -2
x2 = 4498
P1 = 7999/8000
P2 = 1/8000
Substituting to the equation and we will have:
Therefore, the expected value of a single ticket is -1.4375.