To figure out the average of Michael and Melissa we must add up all their test scores and divide the by 7; which is the number of tests they took.
Michael:
(80+76+73+70+40+25+10)/7
Melissa:
(88+83+75+70+60+65+62)/7
Michael's average is 53.4
Melissa's average is 71.9
So Melissa is earning a C in Latin.