Sam scored 43, 48, and 42 points on three tests. How many points should he get on the fourth test to get an average score of 50?

83 points
67 points
45.75 points
44.33 points

Question

Sam scored 43, 48, and 42 points on three tests. How many points should he get on the fourth test to get an average score of 50?

 83 points
 67 points
 45.75 points
 44.33 points

anonymous · Answer

@Freez @confluxepic

matt101 · Answer

You can solve this using a bit of algebra and the equation for an average. You're given the average, and marks for 3 of the 4 tests. You want to find the mark on the 4th test:

$$50={43+48+42+x \over 4}$$
Solve for x and you have your answer!

anonymous · Answer

Average is calculated by dividing the sum of the values in a set by the total number of values in that set.