Answer
x = 70
↓Steps Explained:↓
Given 2 scores of 20, 30:
what should be score number 3
in order to attain an average score of 40?
Setup Average Equation:
| Average = | Sum of our 2 numbers + unknown score of x |
| Total Numbers |
| 40 = | 20 + 30 + x |
| 3 |
Cross Multiply
20 + 30 + x = 40 x 3
x + 50 = 120
Subtract 50 from both sides of the equation to isolate x:
x + 50 - 50 = 120 - 50
Final Answer
x = 70Related Calculators: Number Line Midpoint | 1089 Number Trick | Pentagonal Number