Let a pair of dice be thrown and the random variable X be the sum of the numbers that appear on the two dice. Find the mean or expectation of X.

Asked by Topperlearning User | 4th Jun, 2014, 01:23: PM

Expert Answer:

The S be the sample space, when a pair of dice is thrown.

 
; n(S) = 36
 
The random variable X i.e. the sum of the numbers on the two dice takes the values 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.
 

X or xi
2
3
4
5
6
7
8
9
10
11
12
P(X)
1/36
2/36
3/36
4/36
5/36
6/36
5/36
4/36
3/36
2/36
1/36

 

Answered by  | 4th Jun, 2014, 03:23: PM