You want to plan ahead, specically for something exciting 15 years from now. You believe that your 2-year old son will be attending your dream

You want to plan ahead, specifically for something exciting 15 years from now. You believe that your 2-year old son will be attending your dream school (ya, you read that right). You make excellent predictions and are sure that $70,000 per year is needed for tuition and living expenses (Each year of the college, he needs to pay the $70,000 at the beginning of the year. I.e. the first payment is 15 years from today). In 15 years, you will give him a lump sum payment for the entire amount he will need, assuming that he will be able to invest the money not yet needed at 7% interest per year. You have found an investment opportunity that will yield an annual return of 5% on your monthly payments (monthly payments will be deposited at the end of each month. I.e. the first deposit you will make one month from today). 

How much will you have to invest each month to give your son the money he needs for his education?