# Worksheet for how to calculate Class Interval Arithmetic Mean

Class Interval Arithmetic Mean is the distribution represented by relative frequency counts or proportions of observations within different class intervals. This worksheet help you to understand how to calculate class interval arithmetic mean. The formula used in this calculation, where
f is the frequency
x is the midpoint of the data set

Example
Calculate class interval arithmetic whose intervals are 1-5,6-10,11-15,16-20,21-25 and frequency is 10,20,30,40,50.
Calculate the mid value for intervals:
1-5 = (1+5)/2 = 3
6-10 = (6+10)/2 = 8
11-15 = (11+15)/2 = 13
16-20 = (16+20)/2 = 18
21-25 = (21+25)/2 = 23

The values of X = 3, 8,13,18,23

f = 10, 20,30,40,50
Substitute these values in the above formula,
X = ((3x10)+(8x20)+(13x30)+(18x40)+(23x50))/(10+20+30+40+50)
= (30+160+390+720+1150)/150
= 2450/150
= 16.33333

The class interval arithmetic mean for the given data is 16.33333.

When you try such calculations on your own, this class interval arithmetic mean calculator can be used to verify your results of calculations.