The mean of Hayley’s marks on 5 tests is 77.5%. The marks on the first 4 tests were 88%, 76%, 68%, and 72%, but she lost the fifth test. Find the mark on the fifth test. Show your work.
88+76+68+72 + x = 5*77.5
x = 83.5
Hmmm. I suspect a typo
x = 83.5
Hmmm. I suspect a typo