A census collected data on everyone that lived in a certain small town. The random variable $x$ is the number of girls out of four children born to a randomly selected couple in that town. Its probability distribution is shown below. Complete parts a through $c.$

$\backslash$table$[[x,0,1,2,3,4],[P(x=x),0\mathrm{.}0684,0\mathrm{.}1965,0\mathrm{.}3864,0\mathrm{.}2931,0\mathrm{.}0556]]$

a$.$ Find and interpret the mean of the random variable.

${}_x=,($Round to four decimal places as needed.$)$