Solve.
-A student scored 67, 84, and 94 on three algebra tests. What must he score on the fourth test in order to have an average grade of at least 85?
A)95
B)29
C)61
D)82

Question

Quizplus · Accepted Answer

Let x be the score the student needs on the fourth test to have an average grade of at least 85.

We can use the formula for the arithmetic mean (average) to set up an equation:

(67 + 84 + 94 + x) / 4 ≥ 85

Multiplying both sides by 4 gives:

67 + 84 + 94 + x ≥ 340

Combining like terms:

245 + x ≥ 340

Subtracting 245 from both sides gives:

x ≥ 95

Therefore, the student must score at least 95 on the fourth test to have an average grade of at least 85.

The best choice is A, 95. Let the fourth test score be x. Then, the average grade can be calculated as:
(67+84+94+x)/4 ≥ 85
Simplifying this equation, we get x ≥ 95.
Therefore, the student must score at least 95 on the fourth test to have an average grade of at least 85. The correct answer is choice A.

Solve. -A Student Scored 67, 84, and 94 on Three Algebra