answer this question please

Suppose an H1200 supercomputer has a cost of $300,000 and will have a residual market value of $75,000 in 4 years. The risk-free interest rate is 5.9% APR with monthly compounding. a. What is the risk-free monthly lease rate for a 4-year lease in a perfect market? b. What would be the monthly payment for a 4-year $300,000 risk-free loan to purchase the H1200 ? Note: Round the monthly interest rate to at least six decimal places