BillSplitter.java

import java.util.Scanner;

public class BillSplitter {
    public static void main(String[] args) {
        double total = 0;
        double preTax = 0;
        double ratio = 0;
        double totalShare = 0;
        int peopleCount;
        Scanner intScanner = new Scanner(System.in);
        Scanner stringScanner = new Scanner(System.in);
        Scanner doubleScanner = new Scanner(System.in);

        System.out.println("Total?");
        total = doubleScanner.nextDouble();

        System.out.println("How many people in totoal?");
        peopleCount = intScanner.nextInt();

        Person[] persons;
        persons = new Person[peopleCount];

        for (int i = 0; i < peopleCount; i++) {
            String name;
            double subtotal;

            System.out.println("Person " + i + " name:");
            name = stringScanner.nextLine();
            System.out.println(name + " 's subtotal");
            subtotal = doubleScanner.nextDouble();

            persons[i] = new Person(name, subtotal);
        }

        for (int i = 0; i < peopleCount; i++) {
            preTax += persons[i].value;
        }

        ratio = total / preTax;

        for (int i = 0; i < peopleCount; i++) {
            persons[i].share = shareCalc(persons[i].value, ratio);
            totalShare += persons[i].share;
        }

        for (int i = 0; i < peopleCount; i++) {
            System.out.println(persons[i].name + ": " + persons[i].share);
        }
        
        System.out.println("PreTax Total: "+ preTax);
        System.out.println("Totoal: " + totalShare);
    }

    static double shareCalc(double value, double ratio) {
        return ratio * value;
    }
}

Person.java

public class Person {
    double value;
    String name;
    double share;

    public Person() {
        value = 0;
        name = "";
    }

    public Person(String name, double value) {
        this.name = name;
        this.value = value;
    }

}