Question 292454
The average mark on the first 3 tests Jean took was 76.
 What average mark does Jean need on the next two tests to have an average
 of 80 for all of the tests?
:
Let x = value required on the last two tests to average an 80 for all 5 tests
:
{{{(3(76) + 2x)/5}}} = 80
Multiply both sides by 5
228 + 2x = 5(80)
2x = 400 - 228
2x = 172
x = {{{172/2}}}
x = 86 the average required on the last two tests.