The answer would be 93% because first we need to do the reverse of how to find the mean... 80 * 4 = 320 and so we just have to subtract the grades from 320... 320 - 79 - 66 - 82 = 93... Thus Jordan's grade was 93
The difference would be 0.27
5a.
18/9 = 12/x
18x = 12(9)...cross multiply
18x = 108
x=108/18
x=6
