Java Program to Calculate Standard Deviation

In this program, you’ll learn to calculate the standard deviation using a function in Java.

This program calculates the standard deviation of a individual series using arrays.

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: Program to Calculate Standard Deviation

``````
public class StandardDeviation{

public static void main(String[] args){
double[] numArray = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
double SD = calculateSD(numArray);

System.out.format("Standard Deviation = %.6f", SD);
}

public static double calculateSD(double numArray[]){
double sum = 0.0, standardDeviation = 0.0;
int length = numArray.length;

for(double num : numArray) {
sum += num;
}

double mean = sum/length;

for(double num: numArray) {
standardDeviation += Math.pow(num - mean, 2);
}

return Math.sqrt(standardDeviation/length);
}
}``````

Output

`Standard Deviation = 2.872281`

In the above program, we’ve used the help of Java Math.pow() and Java Math.sqrt() to calculate the power and square root respectively.

Note: This program calculates the standard deviation of a sample. If you need to compute S.D. of a population, return `Math.sqrt(standardDeviation/(length-1))` instead of `Math.sqrt(standardDeviation/length)` from the `calculateSD()` method.

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