In: Statistics and Probability
An urn contains 7 black balls, 4 red balls, 3 white balls and 1 blue ball, and a player is to draw one ball. If it is black, he wins $1, if it is red, he wins $2, if it is white he wins $3 and if it is blue, he pay $25.
a. Set up the empirical probability distribution for the random
variable X, the payoff of the game.
| Game Payoff (X) | Probability [P(X) |
| $1 | |
| $2 | |
| $3 | |
| $4 |
b. What is the mathematical expectation of this game?
c. In the long-run, will the player win or lose?
Solution:
In the question, we are given:
An urn contains 7 black balls, 4 red balls, 3 white balls, and 1 blue ball, and a player is to draw one ball. If it is black, he wins $1, if it is red, he wins $2, if it is white he wins $3 and if it is blue, he pays $25.
Therefore, there are total 7+4+3+1=15 balls.
The probability of drawing a black ball is:

The probability of drawing a red ball is:

The probability of drawing a white ball is:

The probability of drawing a blue ball is:

| Game Payoff (X) | Probability P(X) |
| $1 | 0.46667 |
| $2 | 0.26667 |
| $3 | 0.2 |
| -25 | 0.06667 |
b. What is the mathematical expectation of this game?



c. In the long-run, will the player win or lose?
Answer: In the long-run, the player will
lose.