How to write the total bill in my java project?

import java.util.Scanner;
  
public class PracticeLab3 {
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    Scanner input = new Scanner(System.in);
        
        // Prompt the user to enter the price of the product
        System.out.print("Enter the price of the product: ");
        double costProduct = input.nextDouble();
        // Prompt the user to enter the weight of the package
        System.out.print("Enter the weight of the package: ");
        double weight = input.nextDouble();

        // Calculate cost of shipping
        if (weight > 20)
          System.out.println("The package cannot be shipped.");
        else
        {
          double costPerPound;
          double costShipping;
          double costTotal;
          if (weight > 0 && weight <= 1)
            costPerPound = 3.5;
          else if (weight <= 3)
            costPerPound = 5.5;
          else if (weight <= 10)
            costPerPound = 8.5;
          else //if (weight <= 20)
            costPerPound = 10.5;
          costShipping = costPerPound * weight;
          System.out.println("Shipping cost of package is $" +
            costShipping);
          costTotal = costProduct + costShipping;
          System.out.println("Total amount is $" +
            costTotal);
        }
      }

}