C++ Program to Calculate Standard Deviation

This program calculates the standard deviation of an individual series using arrays. Visit this page to learn about Standard Deviation.

To calculate the standard deviation, calculateSD() function is created. The array containing 10 elements is passed to the function and this function calculates the standard deviation and returns it to the main() function.

Example: Calculate Standard Deviation using Function

#include <iostream>
#include <cmath>
using namespace std;

float calculateSD(float data[]);

int main() {
  int i;
  float data[10];

  cout << "Enter 10 elements: ";
  for(i = 0; i < 10; ++i) {
    cin >> data[i];
  }

  cout << endl << "Standard Deviation = " << calculateSD(data);

  return 0;
}

float calculateSD(float data[]) {
  float sum = 0.0, mean, standardDeviation = 0.0;
  int i;

  for(i = 0; i < 10; ++i) {
    sum += data[i];
  }

  mean = sum / 10;

  for(i = 0; i < 10; ++i) {
    standardDeviation += pow(data[i] - mean, 2);
  }

  return sqrt(standardDeviation / 10);
}

Output

Enter 10 elements: 1
2
3
4
5
6
7
8
9
10

Standard Deviation = 2.87228