Question 379118
To pass a course, a student must have an average on four exams of at least 70.
 If a student scores 40, 78, and 88 on the first three tests,
 what must he earn on the fourth exam to pass the course?
:
Let x = required grade to average at least 70
:
{{{(x + 40 + 78 + 88)/4}}} => 70
Multiply both sides by 4, add up the given values
x + 206 => 280
x => 280 - 206
x => 74 to pass the course