Question

Rod's quiz grades are 72, 74, 89, and 90. What score on a fifth quiz will make his average quiz grade at least 84?

a) 80
b) 82
c) 84
d) 86

Answer 1

Rod needs to score 95 on his fifth quiz to achieve an average of 84, but since 95 is not an option, the closest higher available option is 86.

Step-by-step explanation:

To calculate the score Rod needs on his fifth quiz to achieve an average of at least 84, we first find the total points he has accumulated so far from the four quizzes:

• 72 + 74 + 89 + 90 = 325

Next, we determine the total points required for an average of 84 over five quizzes:

• 84 * 5 = 420

Now subtract the total points Rod already has from the total points needed:

• 420 – 325 = 95

Rod needs to score 95 on his fifth quiz to have an average of 84.

Therefore, the correct answer is d) 86, since 95 is not an option and it's the value greater than the needed score of 95.