Consider the discrete random variable $\displaystyle {X}$ given in the table below. Calculate the mean, variance, and standard deviation of $\displaystyle {X}$.

$\displaystyle {X}$	5	6	7	10	11	18
P($\displaystyle {X}$)	0.07	0.13	0.14	0.06	0.49	0.11

$\displaystyle \mu$ =
$\displaystyle \sigma^{{2}}$ =
$\displaystyle \sigma$ =


Let $\displaystyle {Y}$ = $\displaystyle {X}+{X}$. Find the mean, variance, and standard deviation of $\displaystyle {Y}$.
$\displaystyle \mu$ =
$\displaystyle \sigma^{{2}}$ =
$\displaystyle \sigma$ =


Let $\displaystyle {Z}$ = $\displaystyle {X}-{X}$. Find the mean, variance, and standard deviation of $\displaystyle {Z}$.
$\displaystyle \mu$ =
$\displaystyle \sigma^{{2}}$ =
$\displaystyle \sigma$ =