Question 322722
add all the test scores to x(the unknown score) divided by total tests (5) = 84

{{{(84+82+81+79+x)/5=84}}}
{{{(326+x)/5=841}}}
{{{((326+x)/5)*(5/1)=84*(5/1)}}}
{{{326+x=420}}}
{{{x=94}}}