Imagine a student spends $$20$ daily on eating out, including ultra$-$processed, expensive, addictive, unhealthy fast food and sugary drinks. However, if they decide to switch to preparing their own meals and drinks at home, avoiding processed foods, sugary beverages, and expensive bottled water with microfiber and other harmful chemicals, they could cut their spending to just $$10$ per day and eat healthy. With the savings and the good spirit that comes with eating healthy, they plan to invest the difference at a $5\%$ annual interest rate, compounded monthly. How much would they have saved and earned from their investment after four years? Calculate the PV and FV using the begin and end modes.