Long$-$Life Insurance has developed a linear model that it uses to determine the amount of term life insurance a family of four should have, based on the current age of the head of the household. The equation is:

$y=850-0\mathrm{.}1x$

where

$y=$ Insurance needed $($$$000)$

$x=$ Current age of head of household

b$.$ Use the equation to determine the amount of term life insurance to recommend for a family of four if the head of the household is $30$ years old.

$\backslash$table$[[$Amount of term life insurance,$$,154,$thousands$]]$