Question

Discrete Random variable question:
http://i58.tinypic.com/23m7xw6.png

I got 6.2 for E(R), but I can't seem to figure out how to get E(R^2)?

anyone please! medals will be given :)D

Answer 1

@ganeshie8

Answer 2

@kropot72 ?

Answer 3

\[\large E(R ^{2})=\sum_{}^{}r ^{2}p(r)\]

Answer 4

\[Var(R) = E(R ^{2}) - [E(R)]^{2}\]

Answer 5

thanks I figure it out!

Answer 6

and Standard Deviation is the Square Root of Variance.

Answer 7

\[\large E(R ^{2})=1^{2}\times\frac{1}{5}+5^{2}\frac{2}{5}+10^{2}\frac{2}{5}\]

Answer 8

You're welcome :)