Respuesta :
Answer:
A score between 84 and 99
Step-by-step explanation:
First, let's solve for what you would need to score on your next test to have an average of 84:
(81 + 87 + x)/3 = 84
(168 + x)/3 = 84
168 + x = 252
x = 84
Next, let's solve for what you would need to score on your next test to have an average of 89:
(81 + 87 + x)/3 = 89
(168 + x)/3 = 89
168 + x = 267
x = 99
That means you would have to earn a score between 84 and 99.
I hope this helped you, and if it did, a brainliest would be appreciated :)