test.java

import java.util.*; 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.text.DecimalFormat;

public class Main
{
         public static void main(String[] args) throws IOException
        {
                //try catch block to handle exceptions 
                try 
                {
                        InputStreamReader reader = new InputStreamReader(System.in, StandardCharsets.UTF_8);
                        BufferedReader myReader = new BufferedReader(reader);
                        //read 1st line, we want to skip this because it contain field name 
                        myReader.readLine();
                        //varibles
                        double value,sum=0,count=0,min=999999999,max=0;
                        //ArrayList to store values for finding std
                        ArrayList <Double> al=new ArrayList <Double>();
                        //read from file until line is present
                        String data;
                        while ((data = myReader.readLine()) != null) 
                        {
                                //split string by ,
                                String arr[]=data.split(",");
                                //value is 2nd element of array according to input given in question
                                value=Double.parseDouble(arr[1]);
                                //add value to ArrayList
                                al.add(value);
                                //add value to sum
                                sum+=value;
                                //increment count
                                count++;
                                //calculate max
                                if(value>max)
                                {
                                        max=value;
                                }
                                //calculate min
                                if(value<min)
                                {
                                        min=value;
                                }
                        }
                        //calculate mean
                        double mean=sum/count;
                        double std=0.0;
                        //loop through all values
                        for(double values:al)
                        {
                                //calculate std
                                std+=Math.pow(values - mean, 2);  
                        }
                        std = Math.sqrt(std/count);
                        //print values
                        DecimalFormat d2 = new DecimalFormat("0.00");
                        DecimalFormat d3 = new DecimalFormat("0.000");
                        DecimalFormat d4 = new DecimalFormat("0.0000");
                        System.out.println(d2.format(min));
                        System.out.println(d2.format(max));
                        System.out.println(d3.format(mean));
                        System.out.println(d4.format(std));
                        //close file
                        myReader.close();
                } 
                
                catch (ArithmeticException Ae)
                {
                        System.out.println("Count should be greater than 1 for std");
                }
        }
}