Java Program to Calculate Standard Deviation. A standard deviation is a statistic that measures a dataset’s dispersion from its mean.

By calculating each data point’s divergence from the mean, the standard deviation is calculated as the square root of variance.

## Standard Deviation Program in Java

A data set’s standard deviation is a measure of how spread out it is. It can be found in a wide range of applications.

Standard deviations of price data are commonly used as a measure of volatility in finance.

Standard deviations are an important aspect of estimating margins of error in opinion polling.

A standard deviation is a statistic that measures a dataset’s dispersion from its mean.

There is a bigger variance within the data set if the data points are further from the mean; consequently, the more spread out the data, the higher the standard deviation.

## Double Data Type in Java

A primitive data type in Java is the double keyword. It’s a 64-bit IEEE 754 floating point with double precision. It’s where variables and methods are declared. It is used to represent decimal numbers in general.

Double is more exact than float and can store 64 bits, which is twice as much as float. We favour double over float for storing huge numbers because it is more exact. Standard deviation program in java is executed in this program.

To declare (create) a variable, first state the type, then leave at least one space, then the variable’s name, and finally a semicolon at the end of the line ( ; ).

In Java, the keywords int and double represent integers, double represents a floating point number (a number with double precision), and boolean represents a Boolean value (true or false).

## math.pow in Java

The Math. pow() function converts the base to the exponent power, where the base and exponent are both in the decimal system. java.lang is a programming language that was developed by Sun Microsystems.

A number is raised to the power of another integer using the math. pow() function. This function takes two arguments and returns the first parameter’s value multiplied by the second.

The value of the first parameter raised to the power of the second argument is returned by pow().

The pow() method returns a double value. This is sample program for Standard deviation program in java.

## String args in Java Program to Calculate Standard Deviation

String[] args is an array of type java. lang that contains Java command line parameters. String is a kind of data.

The name of the String array is args in this case, but it is not fixed, and the user can use any name instead.

An array of sequences of characters (Strings) that are supplied to the “main” function is referred to as String[] args. When a program is run, this occurs. This is how to calc standard deviation in java for beginners.

```
public class Main
{
public static void main(String[] args)
{
double[] numArray = { 1, 4,5,6,7,5,8,9, 10 };
double SD = calculateSD(numArray);
System.out.format("SD value is = %.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:

SD value is = 2.601044