Consider the probability distribution for the random variable $x$ shown here. Complete parts a through $c$ below.

$x$

$p(x)$

$200\mathrm{.}05$

$30$

$40$

$50$

$60$

$700\mathrm{.}05$

$$

$\backslash$table$[[20,30],[0\mathrm{.}05,0\mathrm{.}25]]$

$0\mathrm{.}30$

$0\mathrm{.}25$

$0\mathrm{.}10$

$0\mathrm{.}05$

a$.$ Calculate $,{}^2,$ and $$

$=$

$($Type an integer or a decimal. Do not round.$)$