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#include<iostream>
#include<cmath>
using namespace std;
void datapoints(double[],double[] ,int );
void avg(double [],double [],int,double & ,double & );
void sumofsq( double [],double [],int,double &,double &,double &,double & );
void sumofprod(double [],double [],int,double &,double &);
int main ()
{ 
  int n;
  double xbar,ybar,b,a,avesum,sum,asx,asy,r,sumx,sumy,x,y,top,bottom;
    cout <<"How many data points would you like to enter. ";
    cin >>n;
  double pointsx[n];
  double pointsy[n];
    datapoints(pointsx,pointsy,n);// input data values
    avg(pointsx,pointsy,n,xbar,ybar);//ave for x and y values
    sumofsq(pointsx,pointsy,n,sumx,sumy,asx,asy);
    sumofprod(pointsx,pointsy,n,avesum,sum);
      top= (avesum-xbar*ybar);
      bottom=(asx-(xbar*xbar));  
      a=top/bottom;
         b=ybar-(a*xbar);   
     cout<< "The best fit line equation is    y= "<> dpx[i]; // cout<<"Enter the co-ordinates of y for "<> dpy[i]; } }//end of the function void avg(double x[],double y[],int size, double &xave, double &yave) { double sum=0.0; for(int i=0;i