Hello there.
Skylar's grades on four math tests are 85, 78, 77, and 69. What does Skylar need to score on the next test in order to have a mean score of 80?
Answer: 85 + 78 + 77 + 69 = 309.
80 x 5 = 400.
400 - 309 = 91.
She needs to score 91.
Hope This Helps You!
Good Luck Studying ^-^