# C Programming (Turbo C++ Compiler) - Calculate Variance

I have given the simple C program for calculating sample and population variance for a set of numbers. The other related linkes are,

Calculate Mean

Calculate Median

Calculate Mode

Calculate Range

Calculate Variance

Calculate Standard Deviation

## Source Code

#include <stdlib.h>

#include <stdio.h>

#include <math.h>

float CalculateMean(float *value, int max)

{

int i;

float sum = 0;

for( i = 0; i < max; i++)

sum = sum + value[i];

return (sum / max);

}

float CalculateVariane(float *value, int max)

{

float mean = CalculateMean(value, max);

int i = 0;

float temp = 0;

for(i = 0; i < max; i++)

temp += (value[i] - mean) * (value[i] - mean) ;

return temp / max;

}

float CalculateSampleVariane(float *value, int max)

{

float mean = CalculateMean(value, max);

float temp = 0;

int i = 0;

for(i = 0; i < max; i++)

temp += (value[i] - mean) * (value[i] - mean) ;

return temp / (max - 1);

}

int main()

{

float arrNumbers[100];

int i, max;

float mean;

char buf[1024];

float variance, samplevariance;

printf("Total Number of Elements: ");

scanf("%d", &max);

for(i = 0; i < max; i++)

{

printf("Enter [%d] Number: ", i + 1);

scanf("%f", &arrNumbers[i]);

}

printf("\nTotal Numbers: %d", max);

mean = CalculateMean(arrNumbers, max);

variance = CalculateVariane(arrNumbers, max);

samplevariance = CalculateSampleVariane(arrNumbers, max);

printf("\nMean: %f", mean);

printf("\nSample Variance: %f", samplevariance);

printf("\nPopulation Variance: %f",  variance);

return 0;

}

## Output

Total Number of Elements: 10

Enter [1] Number: 6

Enter [2] Number: 7

Enter [3] Number: 8

Enter [4] Number: 7

Enter [5] Number: 6

Enter [6] Number: 5

Enter [7] Number: 2

Enter [8] Number: 2

Enter [9] Number: 9

Enter [10] Number: 3

Total Numbers: 10

Mean: 5.500000

Sample Variance: 6.055555

Population Variance: 5.450000