Use the function rule to complete the table -10+y=4

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

How do i do this? i don’t understand

Write 17/20 as a decimal and as a percent.