Question
In: Statistics and Probability
2 dice are rolled. Let X be the number on the first die, Y - on...
2 dice are rolled. Let X be the number on the first die, Y - on the second, and Z=X - Y. Find the expectation and standard deviation of Z.
Solutions
Expert Solution
| X\Y | 1 | 2 | 3 | 4 | 5 | 6 |
| 1 | 0 | -1 | -2 | -3 | -4 | -5 |
| 2 | 1 | 0 | -1 | -2 | -3 | -4 |
| 3 | 2 | 1 | 0 | -1 | -2 | -3 |
| 4 | 3 | 2 | 1 | 0 | -1 | -2 |
| 5 | 4 | 3 | 2 | 1 | 0 | -1 |
| 6 | 5 | 4 | 3 | 2 | 1 | 0 |
V(X)=5.83-0^2=5.83
So standard deviation is 
orchestra answered 1 year agoRelated Solutions
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