Question

The average number is 85. if three of the numbers are76,78,81 what is the forth number

Answer 1

105

Explanation:

The formula for finding average, a.k.a. mean, is the sum of the terms divided by the number of terms. So to find the 4th number, you need to do 85x4 first, to get 340, which is the sum of the terms(specifically 76, 78, 81, and the unknown number). 76+78+81=235. 340-235=105, therefore 105 is the fourth number.

Answer 2

The fourth number is 105