Question 54869
A student averages 84 on five tests. If the student received grades of 84, 82, 81, and 79 on the first four exams, what grade did the student receive on the fifth exam?
Let the grade for the fifth exam=x
You find the average by adding all the grades together and dividing by the number of tests.
{{{(84+82+81+79+x)/5=84}}}
{{{(326+x)/5=84}}}
{{{5(326+x)/5=5(84)}}}
{{{cross(5)(326+x)/cross(5)=420}}}
{{{326+x=420}}}
{{{-326+326+x=420-326}}}
{{{highlight(x=94)}}}
:
Check substitute 94 in for x and see if the student averages 94.
{{{(84+82+81+79+94)/5=84}}}
{{{420/5=84}}}
{{{84=84}}} We're right!!!
Happy Calculating!!!