Your scores for the semester are 87, 84, and 85. can you raise your test average to 90 with your next test?

Question

i need to write an equation to solve the problem. please help me. i start school tomorrow. thank you.

Answer 1

You would have to make a 104 on a test to bring the average up to 90.

(84+85+87 +a)/4= 90

256 + a = 90 x 4

256 + a=360

a=360-256

a=104

Answer 2

Nope

I'll assume all these tests had a 100 maximum as well as the new one

Try to write an equation and solve for the unknown

Average = 90 = (87+84+85+new test score)/4

90*4 = 87 +84 + 85 + new test score

360 = 256 + new test score

360 - 256 = new test score

104 = new test score

So, unless you can get some kinda extra credit best you can do is 90 (with a perfect 100  

Answer 3

so you need the average of 4 test scores to be 90

(x+87+84+85)/4 = 90

solve for x

x=104

if the test score maximum is 100, you cannot raise your test average to 90