Question

a student has test scores of 92%, 87%, and 78%. what must she need to score on thenlast test to maintain 80% or better?

Answer 1

We'll solve this equation in order to find the score of the 4th test, which we denote with x. $\frac{92+87+78+x}{4}=80$. Solving it we find that x=63. And it is the final answer for this problem.