Total students in the class who got the quiz = 28
The average of the class average was = 82.5
Five students that were absent made up the quiz after school and their scores were a 78, 89,92,99, & 63.
The formula for an average= (sum of values) / (count of values)
As the average is given as 82.5 and there were 28 students, so sum of the 28 values will be =
Total students of the class = 28+5(absent) = 33
For 33 students the total score was = 2310 +(78+89+92+99+63)
= 2731
So, average for 33 students will be = or 82.76
So, the new class average is 82.76