Keshia is opening a bookkeeping service. she is considering buying or leasing some new laptop computers. the purchase price of a laptop is $1,500 and after three years it is worthless. the annual lease rate is $550 per laptop. the value of marginal product of one laptop is $700 a year. the value of marginal product of a second laptop is $625 a year. the value of marginal product of a third laptop is $575 a year. and the value of marginal product of a fourth laptop is $500 a year. how many laptops will keshia lease or buy? if the interest rate is 4 percent a year, will keshia lease or buy her laptops? if the interest rate is 6 percent a year, will keshia lease or buy her laptops?