In: Statistics and Probability
Take 3 dice and throw these dice 30 times. Let X be the sum of the number of dots on upper faces of the dice.
Obtain probability distribution of X. Also find mean and variance.

| X | fav cases | p(x) | X.p(x) | X^2.P(x) |
| 3 | 1 | 0.00463 | 0.00463 | 0.00463 |
| 4 | 3 | 0.013889 | 0.041667 | 0.125 |
| 5 | 6 | 0.027778 | 0.166667 | 1 |
| 6 | 10 | 0.046296 | 0.462963 | 4.62963 |
| 7 | 15 | 0.069444 | 1.041667 | 15.625 |
| 8 | 21 | 0.097222 | 2.041667 | 42.875 |
| 9 | 25 | 0.115741 | 2.893519 | 72.33796 |
| 10 | 27 | 0.125 | 3.375 | 91.125 |
| 11 | 27 | 0.125 | 3.375 | 91.125 |
| 12 | 25 | 0.115741 | 2.893519 | 72.33796 |
| 13 | 21 | 0.097222 | 2.041667 | 42.875 |
| 14 | 15 | 0.069444 | 1.041667 | 15.625 |
| 15 | 10 | 0.046296 | 0.462963 | 4.62963 |
| 16 | 6 | 0.027778 | 0.166667 | 1 |
| 17 | 3 | 0.013889 | 0.041667 | 0.125 |
| 18 | 1 | 0.00463 | 0.00463 | 0.00463 |
| 216 | 1 | 20.05556 |
455.4444 |