Statistics Programme

import java.util.ArrayList;
import java.util.Scanner;

public class Stat {

    // Methods
    public static void displayList(ArrayList <Double> list) {
        for(int i=0; i<list.size(); i++) {
            System.out.println("Index " + i + ": " + list.get(i));
        }
    }

    // 1. Find the average
    public static double findAverage(ArrayList <Double> list) {
        double sum = 0;
        for(int i=0; i<list.size(); i++) {
            sum += list.get(i);
        }
        return (sum / list.size());
    }

    // 2. Find the variance
    public static double findVariance(ArrayList <Double> list){
        double sum = 0;
        for(int i=0; i<list.size(); i++) {
            sum += list.get(i) * list.get(i);
        }
        sum -= (list.size() * findAverage(list) * findAverage(list));
        sum /= (list.size() - 1);
        return sum;
    }

    // 3. Find the mean
    public static double findMean(ArrayList <Double> list) {
        if(list.size() % 2 == 0) {
            int index = (int)((list.size() - 1) / 2);
            return (list.get(index) + list.get(index+1)) / 2;
        }
        else {
            int index = (list.size() - 1) / 2;
            return list.get(index);
        }
    }



    // MAIN FUNCTION
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        System.out.println("Start giving me values and this process will stop, when you ");
        System.out.println("type 'as value' the NUMMBER -1000000 (-1 million)");
        System.out.println();
        double value = 0;
        int counter = 0;
        ArrayList <Double> list = new ArrayList <Double> ();
        while(value != -1000000) {
            counter++;
            System.out.print("Value " + counter + ": ");
            value = scanner.nextDouble();
            list.add(value);
        }
        // I have to remove the last element, which is -1000000 and indicated the stop of the session above
        System.out.println();
        list.remove(list.size()-1);
        // 1. I find the average
        double average = findAverage(list);
        System.out.println("* Average = E[X] = " + average);
        // 2. I find the variance and the standard deviation
        double var = findVariance(list);
        System.out.println("* Variance = σ^2 = " + var);
        System.out.println("* Standard Deviation = σ = " + Math.sqrt(var));
        // 3. I find the mean
        double mean = findMean(list);
        System.out.println("* Mean = x~ = " + mean);

    }   // END OF MAIN FUNCTION

}   // END OF CLASS