You can pay $91 per month, starting next month, for the next 5
years to have a lawn mowing service. Alternatively, you can
purchase a riding lawn mower and pay $506 today and mow your own
lawn for 5 years, starting next month. If you decide to mow your
own lawn, how much do you save in PV terms if your investments earn
3.31% APR, compounded monthly? Note: If you would lose money, make
your answer with a negative sign...