I need help fixing my code. The program is about finding the mean and standard deviation.

Sample output. Using the following data files

sort1.txt:100 90 75 80

sort2.txt:99 92 60 75 70

sort3.txt:99 92 60 75 70 50

Your output (with a couple of debug statements thrown in) might be:

Enter the name of the first filesort1.txt

Enter the name of the second filesort2.txt

Enter the name of the third filesort3.txt

task1 returns count = 4, sum = 345

task2 returns count = 5, sum = 396

task3 returns count = 6, sum = 446

Driver newMean = 79.133333

Driver sumDiffsSq: 571.337778 1026.822222 1875.573333

Totals sum = 1187, count = 15, sumDiffsSq = 3473.733333

Average = 79.13

Standard Deviation = 15.75

My code:

import java.util.Scanner; import java.io.File; import java.io.FileNotFoundException; import java.io.*; import java.text.DecimalFormat; public class HadoopSim implements Runnable {  private final int SIZE = 100;  private int [] arrayData = new int [SIZE];  private int count = 0;  private int sum = 0;  private double sumDiffsSq = 0.0;  private String fileName;  private Scanner scan;  private double newMean = 0.0;  //Constructor to help read the file using Scanner  public HadoopSim(String filename)  {    scan = new Scanner(System.in);    try    {     File file = new File(filename);     scan = new Scanner(file);     int i=0;          while(scan.hasNextLine())     {       arrayData[i] = scan.nextInt();       count++;       sum += arrayData[i];       i++;     }     scan.close();    }    catch (FileNotFoundException e)    { System.out.println("File " + filename + " could not be found."); System.exit(1); }  }    @Override  public void run()  {  }     //count is set when reading the file   public int getCount()   {     return count;   }   //sum is set ina thread by tun() method   public int getSum()   {     return sum;   }   //call after all threads have been completed   public void setNewMean(double m)   {     newMean=m;   }   //method to compute each task;s sum of differneces quared using new mean   public double setSumDiffSqs()   {   // System.out.println(newMean);     double x=0.0;        for(int i=0;i// System.out.println(arrayData[i]);          if(arrayData[i]!=0)           x+= (Math.abs(newMean-arrayData[i])* Math.abs(newMean-arrayData[i]));          //System.out.println(x);        }        sumDiffsSq+=x;      return x;   }   //returns the sum of differences squared for the data in each task's array   public double getSumDiffSqs()   {     return sumDiffsSq;   }   } 

import java.util.Scanner; import java.io.*; import java.text.DecimalFormat; public class HadoopDriver {  public static void main(String[] args)  {    Scanner scan = new Scanner(System.in);    System.out.println("Enter the name of first file ");    String file1 = scan.nextLine();      System.out.println("Enter the name of second file ");    String file2 = scan.nextLine();       System.out.println("Enter the name of third file ");    String file3 = scan.nextLine();    //File file3 = new File(input.next());    scan.close();       HadoopSim h=new HadoopSim(file1);     Thread thread = new Thread(h);     thread.start();     int c1=h.getCount();     int sum1=h.getSum();     System.out.println(" Task1 return count = "+c1 +" and sum = "+sum1);     HadoopSim h2=new HadoopSim(file2);     Thread thread2 = new Thread(h2);     thread2.start();     int c2=h2.getCount();     int sum2=h2.getSum();     System.out.println("Task2 return count = "+c2 +" and sum = "+sum2);     HadoopSim h3=new HadoopSim(file3);     Thread thread3 = new Thread(h3);     thread3.start();     int c3=h3.getCount();     int sum3=h3.getSum();     System.out.println("Task3 return count = "+c3 +" and sum = "+sum3);     double final_sum=sum1+sum2+sum3;     double final_count=c1+c2+c3;     h.setNewMean(final_sum/final_count);     double mean=final_sum/final_count;     double sd= h.setSumDiffSqs();     h2.setNewMean(final_sum/final_count);     double sd2=h2.setSumDiffSqs();     h3.setNewMean(final_sum/final_count);     double sd3= h3.setSumDiffSqs();     System.out.println(" Driver newMean is = "+mean);     System.out.println("Driver sumDiffsSq = "+sd +" "+sd2+" "+sd3);     System.out.println("Total Sum = "+ final_sum+" , count = "+final_count+" , sumDiffsSq = "+(sd+sd2+sd3));     double avg=final_sum/final_count;     DecimalFormat df = new DecimalFormat("#.##");     System.out.println("Average = "+df.format(avg));     System.out.println("Standard Deviation = "+ Math.sqrt((sd+sd2+sd3)/final_count));  } }