using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public void Main()

    {

        var x = new List<double>{

            0,

            0.9,

            3.3,

            4.5,

            9.9,

            15.6,

            23.4,

            34.2,

            48.3,

            62.5,

            77.6,

            93.3,

            110,

            127,

            139.8

        };

        var y = new List<double>{

            6434.139,

            6433.460,

            6432.781,

            6430.064,

            6428.025,

            6431.422,

            6423.267,

            6411.019,

            6398.070,

            6343.310,

            6328.183,

            6323.364,

            6302.678,

            6300.606,

            6284.013

        };

​

        var slope = Getslope(x,y);

        // Console.WriteLine(slope);    

    }

    private double Getslope(List<double> x, List<double> y)

    {

        var xSqSum = x.Select(a => a * a).Sum();

        var xys = Enumerable.Zip(x, y, (a, b) => new { x = a, y = b });

​

        double xbar = x.Average();

        double ybar = y.Average();

​

        // Formula to get the Slope.

        double slope = xys.Sum(xy => (xy.x - xbar) * (xy.y - y.Sum())) / x.Sum(a => (a - xbar) * (a - xbar));

        // Formula to get the Intercept.

        double intercept = ybar - (slope * xbar);

        Console.WriteLine(slope);   

        Console.WriteLine(intercept);   

​

        return slope;

    }

}