When $70 is invested monthly with an annual compound interest rate of 12% interest, compounded monthly, what is the total amount of the investment at the end of the second month? Round the answer to two decimal places as needed.
The total amount of the investment at the end of the second month is $_____
After 2 months, the investment has accumulated 2 months of 12%/12 = 1% of compound interest each.
Therefore, the investment would be increased by 70*1% = $<<70*1*.01=0.70>>0.70 in interest after the first month.
This means the total amount of the investment at the end of the first month is 70+0.70 = $70.70.
After the second month, the investment would be increased by another 70*1% = $<<70*1*.01=0.70>>0.70 in interest.
Therefore, the total amount of the investment at the end of the second month is 70.70+0.70 = $<<70.7+0.7=71.4>>71.40. Answer: \boxed{71.40}.