Answer:
77
Step-by-step explanation:
Average: avg = (n₁ + n₂ + n₃ +...)/n
Plug in: 80 = (82 + 89 + x + 74 + 78)/5, where x = points scored in game 3
Add: 80 = (323 + x)/5
Multiply: 400 = 323 + x
Subtract: x = 77
