x -5 -1 2 7 10

P(x)0.15 0.08 0.22 0.18 0.37

Determine the expected value of x.

Determine the standard deviation of x.

Printable View

- Jul 25th 2012, 10:06 PMnumbaoneazn1Help with standard deviation & expected value please
x -5 -1 2 7 10

P(x)0.15 0.08 0.22 0.18 0.37

Determine the expected value of x.

Determine the standard deviation of x. - Jul 26th 2012, 01:45 AMBAdhiRe: Help with standard deviation & expected value please
Stick to the definitions,

$\displaystyle E(X)=\Sigma_{i=1}^{n}x_iP(x_i)}$

and

$\displaystyle SD(X)=\sqrt{\Sigma_{i=1}^{n}\left[x_i-E(X)\right]^2P(x_i)}}$ or

$\displaystyle SD(X)=\sqrt{E(X^2)-E(X)^2}$

Next time please show where you cannot understand, because for me this seems quite basics (Nod)