A parent wants to create a college investment fund for his son who has just turned 8 years old. The father expects his son to enter university in exactly 10 years, so he plans to deposit a fixed amount of magnitude D monthly from the end of the month (t = 1) and until his son finishes university within 168 months (ie 168 total deposits). Upon entering the university, the fund will be used to withdraw tuition payments and semester academic fees that are expected to total $ 325,000 (within 10 years exactly, that is, the cost of the first semester for your child will be of this amount), and in the same way it is estimated that from that first semester, the total cost of the university will increase by 3% semester for the rest of the student's professional career.