Question 229554
If you averaged 76% on two 100 point tests, what would you have to score on the next 80 point test to raise your average to 80%?
:
Let x = score required to accomplish this:
:
{{{(.76 + .76 + (x/80))/3}}} = .80
Multiply equation by 3
.76 + .76 + {{{x/80}}} = 3(.80)
:
1.52 + {{{x/80}}} = 2.40
:
Multiply equation by 80
1.52(80) + x = 2.4(80)
121.6 + x = 192
x = 192 - 121.6
x = 70.4 has to be scored on this 80 point test
:
:
Check solution
{{{(.76 + .76 + (70.4/80))/3}}} = .80
{{{(.76 + .76 + .88)/3}}} = .80
{{{2.4/3}}} = .8 which is 80%