Processing math: 100%

Discrete Series Arithmetic Mean



When data is given along with their frequencies. Following is an example of discrete series −

Items 5 10 20 30 40 50 60 70
Frequency 2 5 1 3 12 0 5 7

For discrete series, the Arithmetic Mean can be calculated using the following formula.

Formula

ˉx=f1x1+f2x2+f3x3........+fnxnN

Alternatively, we can write same formula as follows −

ˉx=fxf

Where −

  • N = Number of observations

  • f1,f2,f3,...,fn = Different values of frequency f.

  • x1,x2,x3,...,xn = Different values of variable x.

Example

Problem Statement

Calculate Arithmetic Mean for the following discrete data −

Items 14 36 45 70
Frequency 2 5 1 3

Solution

Based on the given data, we have −

Items Frequency
f
fx
14 2 28
36 5 180
45 1 45
70 3 210
  N=11 fx=463

Based on the above mentioned formula, Arithmetic Mean ˉx will be −

ˉx=46311=42.09

The Arithmetic Mean of the given numbers is 42.09.

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