C Program For Arithmetic, Harmonic and Geometric Mean

If n numbers are given this C program calculates the arithmetic mean, harmonic mean and geometric mean of those n numbers using the respective formulae.

Calculate Arithmetic Mean

To find arithmetic mean we know that

Arithmetic mean Formula = sum of all numbers / count of numbers

Example: Arithmetic mean of (10,20,30) = (10+20+30)/3 = 60/3 = 20

Calculate Harmonic Mean

A harmonic mean is another kind of average. To find the harmonic mean of a set of n numbers, add the reciprocals of the numbers in the set and then divide the sum by n and then take the reciprocal of the result.

The harmonic mean of {a1, a2, a3, a4, . . ., an} is given below

Calculate Geometric Mean

There are two methods to find the geometric mean of n numbers.

Find Geometric mean using logarithm

Add the logarithmic values for each number in the set of values given.

Example: Geometric mean of (7,9,12) = log₁₀7 + log₁₀9 + log₁₀12 = 2.87852179

Now divide the sum by number of values in the set, in our case 3

Hence Geometric mean (7,9,12) = 2.87852179/3 = 0.959507265

Now take the antilog of the quotient to find out the geometric mean for given set of values (7,9,12)

antilog(0.959507265) =10^0.959507265 = 9.11

Geometric Mean Without Using Logarithm

Multiply the values you want to find geometric mean for.

Example: Geometric mean of (3,5,12) = 3x5x12 = 180

Now find the nth root of product where n is the number of values in the given set.

In our case Geometric mean (3,5,12) = ∛(180) ≈ 5.65

It is same as writing (180)^1/3>

C Program to Find Arithmetic, Harmonic and Geometric Mean of n Numbers

/* Aim:C code to calculate the Arithmetic Mean and Harmonic Mean of two numbers */

#include<stdio.h>
#include<math.h>
int main()
{
    int i, op, size;
    float sum = 0, Arithmetic_Mean, Harmonic_Mean, Geometric_Mean,numbers[100];
 
    printf("\n How many numbers to accept:- ");
    scanf(" %d",&size);
    
    //accept the numbers
    for(i=0;i<size;i++)
    {
      printf("\n Enter %d th number: ",i+1);
      scanf(" %f",&numbers[i]);
    }
    
    do{
          printf("\n\n 1. Arihmetic Mean");
          printf("\n 2. Harmonic Mean");
          printf("\n 3. Geometric Mean \n");
 
          printf("\n Which operation do you want to perform:- ");
          scanf(" %d",&op);
 
    switch(op)
    {
        case 1:
            for(i=0;i<size;i++)
            {
              sum += numbers[i];
            }
            
            Arithmetic_Mean = sum/size;
            
            printf("\n\n The Arithmetic Mean is   : %f", Arithmetic_Mean);
            break;

        case 2:
            for(i=0;i<size;i++)
            {
            sum += (1/numbers[i]);
            }
            
            Harmonic_Mean = size/sum;

            printf("\n\n The Harmonic Mean is   : %f", Harmonic_Mean);
            break;

        case 3:
            sum = 1;
            for(i=0;i<size;i++)
            {
               // we will store the product of all numbers
               // in sum varibale
            sum *= numbers[i];
            }
            
            Geometric_Mean = pow(sum,(float)1/size);
            
            printf("\n\n The Geometric Mean is   : %f", Geometric_Mean);
            break;
         
     }
  }while(op!=4);    
    
    return 0;
    
}

Output:

 How many numbers to accept:- 3
 Enter 1 th number: 10
 Enter 2 th number: 20
 Enter 3 th number: 30

 1. Arihmetic Mean
 2. Harmonic Mean
 3. Geometric Mean 
 
 Which operation do you want to perform:- 3

 The Geometric Mean (x̄g) is   : 18.171207
 
 How many numbers to accept:- 3
 Enter 1 th number: 10
 Enter 2 th number: 20
 Enter 3 th number: 30

 1. Arihmetic Mean
 2. Harmonic Mean
 3. Geometric Mean 
 
 Which operation do you want to perform:- 3

 The Harmonic Mean (H) is   : 16.36363636
 
 How many numbers to accept:- 3
 Enter 1 th number: 10
 Enter 2 th number: 20
 Enter 3 th number: 30

 1. Arihmetic Mean
 2. Harmonic Mean
 3. Geometric Mean 
 
 Which operation do you want to perform:- 3

 The Arithmetic Mean (μ) is   : 20.00000