Camilla invested $X in her TFSA at the end of every three months for 7 years. Her TFSA is linked to an index mutual fund that returns around 5.2% p.a. compounded semiannually for the first four years followed by 5% p.a. compounded monthly for the next three years. After 7 years, she gave the deposit to her son to aid in the purchase of an apartment in the future. Her son left the deposit in a savings account that earned interest at 4.5% p.a. compounded monthly and the balance of the savings account after 4 years is $41,876.38. Compute X.