Question

We are tossing a pair of 5 sided dice. The experiment is to find the mean and standard deviation.

Fill in a table with three columns, with the Random variable, P(X), and x* P(x)

Answer 1

The question is somewhat incomplete , the random variable is not mentioned .

I assuming the random variable as the sum of the two face values .

and we are assuming the dice are fair .

X		P{X=x)	x.P{X=x]
2	(1,1)	(1/25)	0.08
3	(1,2);(2,1)	(2/25)	0.24
4	(1,3);(2,2);(3,1)	(3/25)	0.48
5	(1,4);(2,3),(3,2);(4,1)	(4/25)	0.8
6	(1,5);(2,4),(3,3);(4,2),(5,1)	(5/25)	1.2
7	(2,5);(3,4);(4,3);(5,2)	(4/25)	1.12
8	(3,5);(4,4);(5,3)	(3/25)	0.96
9	(4,5);(5,4)	(2/25)	0.72
10	(5,5)	(1/25)	0.4
	Total	1	6