Question

A student has scores of 77, 78.5, and 82.75 on his first three tests. He needs an average of at least 80 to earn a grade of B. What is the minimum score that the student needs on the fourth test to ensure a B?

Answer 1

To calculate the minimum score the student needs on the fourth test to ensure an average of at least 80, you can use the following equation:

(77 + 78.5 + 82.75 + x) / 4 ≥ 80

Where x represents the score on the fourth test.

Now, let's solve for x:

(77 + 78.5 + 82.75 + x) / 4 ≥ 80

238.25 + x ≥ 80 * 4

238.25 + x ≥ 320

Now, subtract 238.25 from both sides of the inequality:

x ≥ 320 - 238.25

x ≥ 81.75

So, the student needs a minimum score of 81.75 on the fourth test to ensure an average of at least 80 and earn a grade of B. Since test scores are typically whole numbers, the student would need to score 82 or higher on the fourth test to guarantee a B.