In: Statistics and Probability
You pay $1 to play a game. The game consists of rolling a pair of dice. If you observe a sum of 7 or 11 you receive $4. If not, you receive nothing. Compute the expected value and standard deviation for this game?
Hello Sir/ Mam
YOUR REQUIRED ANSWERS ARE
Expected Value | -0.11 |
S.D. | 2.2879 |
Given that:
Payment to play the game = $1
If sum 7 or 11, then = $4
Otherwise, = $0
We know that:
x | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
P(X=x) | 1/36 | 2/36 | 3/36 | 4/36 | 5/36 | 6/36 | 5/36 | 4/36 | 3/36 | 2/36 | 1/36 |
Dice Outcome | Earnings | Probability |
7 or 11 | 3 | 0.2222 |
Otherwise | -1 | 0.7778 |
Hence,
Dice Outcome | Earnings | Probability | E*P |
7 or 11 | 3 | 0.2222 | 0.67 |
Otherwise | -1 | 0.7778 | -0.78 |
Expected Value | -0.11 |
Dice Outcome | Earnings | Probability | E*P | (Earnings-Mean)^2 |
7 or 11 | 3 | 0.2222 | 0.67 | 9.68 |
Otherwise | -1 | 0.7778 | -0.78 | 0.79 |
Total | -0.11 | 10.47 |
Now,
I hope this solves your doubt.
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