Averages - Complete Guide for SSC Exams
Average Concepts
Basic Formula
Average = Sum of observations/Number of observations
Sum = Average × Number of observations
Important Properties
- If all numbers increase by x, average increases by x
- If all numbers are multiplied by x, average is multiplied by x
Weighted Average
Weighted Avg = (w1×a1 + w2×a2 + ...)/(w1 + w2 + ...)
Solved Example
Question: Average of 5 numbers is 20. If one number 15 is replaced by 30, find new average.
Solution:
Increase = 30 - 15 = 15
Increase in avg = 15/5 = 3
New average = 20 + 3 = 23
BETA
