Question

i have a probability question . two dices are tossed once. let the random variable be t he sum of the up faces on the dice. A). find and graph the probability distribution of the random variable. and b) calculate the mean (or expectation) of this distribution

Answer 1

there are 36 possibilities so prob = 1/36
sum can be 2,3...,12
1 way to get 2 and 12 --> p = 1/36
2 ways to get 3 and 11 -->p = 2/36
3 ways to get 4 and 10 --> p=3/36
4 ways to get 5 and 9 --> p = 4/36
5 ways to get 6 and 8 --> p=5/36
6 ways to get 7 --> p =6/36

E = 7