3. Sean borrowed some money at 7.5% per year, compounded semi-annually. After 3 years, he paid $2244.92 to pay off the loan. What sum of money did Sean borrow? 4. Derek invests $250 per month for 6 years at 4.8% / a compounded monthly. How much will his investment be worth at the end of the 6 years? For each question below, provide well-organized solutions showing all required steps. While calculators may be used for numerical calculations, other mathematical steps must be shown and justified in your written solutions and specific marks may be allocated for these steps. Be sure to demonstrate your understanding of the grade 11 course material by justifying your answers using the knowledge and skills learned in our class..