C++ 计算标准差程序

编写一个C++程序来计算标准差，并附带示例。在此示例中，我们允许用户使用for循环输入项目总数及其价格。

接下来，我们使用另一个for循环来找出所有产品价格的总和。另一个for循环用于方差总和。如果您不想让用户决定产品及其价格，则可以声明并跳过for循环。

#include<iostream>
#include<math.h>
using namespace std;

int main()
{
	float Price[50], SD, Mean, Variance, Sum = 0, Varsum = 0;
	int  i, Number;
	
	cout << "Please Enter the N Value  =  ";
	cin >> Number;
	
	cout << "Please Enter the Real Numbers upto " << Number <<"\n";
	for(i = 0; i < Number; i++)
	{
		cin >> Price[i];
	}	
	for(i = 0; i < Number; i++)
	{
		Sum = Sum + Price[i];
	}
	Mean = Sum / (float)Number;
   
	for(i = 0; i< Number; i++)
	{
		Varsum = Varsum + pow((Price[i] - Mean),2);
	}
	Variance = Varsum / (float)Number;
	SD = sqrt(Variance);
   
	cout << "\nMean                = " << Mean;
	cout << "\nVarience            = " << Variance;	
	cout << "\nStandard deviation =  " << SD;
		
 	return 0;
}

使用函数计算标准差的C++程序

#include<iostream>
#include<math.h>
using namespace std;

float StandardDeviation (float Price[], int Number)
{
	float Mean, Variance, SD, Sum = 0, Varsum = 0;
  	int i;
  	
  	for(i = 0; i<Number; i++)
	{
		Sum = Sum + Price[i];
	}
	Mean = Sum /(float)Number;
   
	for(i=0; i<Number; i++)
	{
		Varsum = Varsum + pow((Price[i] - Mean),2);
	}
	Variance = Varsum / (float)Number;
	SD = sqrt(Variance);
   
	cout << "\nMean                = " << Mean;
	cout << "\nVarience            = " << Variance;
	return SD;
}

int main()
{
	float Price[50], SD;
   int  i, Number;
	
	cout << "Please Enter the N Value  =  ";
	cin >> Number;
	
	cout << "Please Enter the Real Numbers upto " << Number <<"\n";
	for(i = 0; i < Number; i++)
	{
		cin >> Price[i];
	}
	
	SD = StandardDeviation (Price, Number);
	
	cout << "\n\nStandard deviation =  " << SD;
		
 	return 0;
}

Please Enter the N Value  =  5
Please Enter the Real Numbers upto 5
11.55 22.90 33.70 70 60.87

Mean                = 39.804
Varience            = 495.373

Standard deviation =  22.257