A student must have an 83% average to take algebra. I f he has and 82, 77 and 75 in the first three quarters, what is the minimum score he must earn in the 4th

Question

We got 98 but used guess and check method which is not allowed, how else could you get 98 with out guessing.  We started at 100 and worked down.

Answer 1

Let's call the minimum score x

 

We want the average of the 4 quarters to be greater than or equal to 83.

 

So we add them up and divide by how many there are. Then we set it equal to the average we want

 

(82 + 77 + 75 + x) / 4 = 83

 

Solve this equation for x to get your answer

Answer 2

Use the formula for computing the average:

 

(82+77+75+x)/4 = 83

 

Solve for x