Sagot :
Answer:
76
Step-by-step explanation:
In order for John's average to be 80, the sum of all of his test scores must be 4*80 = 320. We can add 84, 78, and 82 to get 244, and then we subtract 244 from 320 to obtain the answer 76.
Answer:
Step-by-step explanation:
80 * 4 = 320
84 + 78 + 82 + x = 244
244 + x = 320
x = 320 - 244
x = 76