matt has the following grades in his science class: 92, 85, 96, and 100. of he has one more test to take in the class, what score must he have to make an average of 90?

Answer 1

To find the average, add up all numbers and divide by how many numbers there are.
(88+84+92+x)/4=90
88+84+92+x=90*4
264+x=360
x=96.
The student has to make a 96.

Answer 2

If the amounts of rainfall in an area over a month are 1.7", 2.2", 0.5", 0.72", and 1.1" what is the mean amount of rainfall in the area for the month?