Question

A student wants to earn a C for a class. To get this grade, the average of his six test scores must be 70.

He has the following grades on five tests:


60,78,65,68,72

What grade must the student get on the next test so that the average of his scores is 70?

Answer 1

Answer: To find out what grade the student must get on the next test, we can use the following formula:

(current total of scores + desired score) / (total number of scores) = desired average

We know that the student's current total of scores is 60 + 78 + 65 + 68 + 72 = 363, and the desired average is 70. We also know that the student has taken five tests, so there is one test remaining.

Therefore, we can plug in these values into the formula:

(363 + x) / 6 = 70

Where x is the grade the student must get on the next test.

We can solve for x by multiplying both sides of the equation by 6:

363 + x = 420

x = 57

Therefore, the student must get a grade of 57 on the next test in order to have an average of 70.

Explanation: