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?

Answer 1

Average score = (sum of scores)/(# of scores)

Therefore, multiplying both sides by # of scores

(Average score)(# of scores) = sum of scores

The average score he wants is 50. There are 4 tests total. As for the sum of scores, let the fourth test be x since he hasn’t taken it yet. The other three scores are 42, 43, and 48.

So the sun of all four scores is 42 + 43 + 48 + x

Plugging the appropriate quantities into the formula

50*4 = (42 + 43 + 48 + x)

Solve for x