Question 456443
Let {{{x}}} = grade she must have on 5th
test to get an A average
{{{ (92 + 99 + 84 + 91 + x) / 5 = 90 }}}
{{{ 92 + 99 + 84 + 91 + x = 450 }}}
{{{ 366 + x = 450 }}}
{{{ x = 450 - 366 }}}
{{{ x = 84 }}}
An 84  on the 5th
test will give her an A average