### oefening 3 ###

public class aModel {

    ArrayList<Integer> cijferList = new ArrayList<>();

    public aModel() {

    }

    public void addToLijst(int newNumber) {
        cijferList.add(newNumber);
    }

    public ArrayList getLijst() {
        return cijferList;
    }

    public double getGemiddelde() {
        double gemidDouble = calcGemiddelde(cijferList);
        return gemidDouble;
    }

    private double calcGemiddelde(ArrayList<Integer> numberList) {
        Integer sum = 0;
        if (!numberList.isEmpty()) {
            for (Integer numList: numberList) {
                sum = sum + numList;
            }
        }
        return sum.doubleValue() / numberList.size();
    }
}