joe needs to have at least an 80 average for the semester. His teacher uses 4 grades to determine the average. If he already had grades of 75,82, and 71, what must his final grades be to meet his goal?
(75 + 82 + 71 + x)/4 = or > 80
Solve for x.
To determine what grade Joe needs to achieve in order to have at least an 80 average for the semester, we need to calculate the average of his four grades.
Let's denote the average we are trying to find as x.
We know that Joe already has three grades: 75, 82, and 71.
To find the fourth grade, we can set up an equation to calculate the average:
(75 + 82 + 71 + x) / 4 = 80.
To get Joe's needed final grade, we can solve this equation for x:
75 + 82 + 71 + x = 4 * 80.
228 + x = 320.
x = 320 - 228.
x = 92.
Therefore, Joe must achieve a grade of at least 92 in his final assignment to meet his goal of an 80 average for the semester.