Question

Joes test grades In history class are:92,89,85,89,and 90. The semester final will count as 40%. Joe needs to get a grade of 90 or higher for the semester. What is the minimum joe can get on the final test and average 90?

Answer 1

let the semester final score = x
let the average of the other four scores = y

grade for the whole class = 40% * x + 60% * y, due to the final being weighted 40%. this whole expression must be ≥ 90 if he wants a 90 average

we'll solve the equation for x, but first we need to fill in the y (average of all the other scores). to find this, simply add up the other four test scores and divide by 4. this will become your y-value.

once you have your y-value, plug it into the first inequality, then solve for x