For part a)

If you want the present value, then it is good.

For b)

I assume she made the down payment, you have to accumulate the 10 missed payment using the future value forumla :

Now remeber that this formula gives you what she owe at time 10 not eleven, accumulate it one time : 3036.97(1.0067) = 3268.44$ Now this is the tricky part, we have accumulated this amount at time eleven and she is to make a payment a time 11, hence use the annuity due formula to get the present value of all the future payment (26 payments): Add the PV and the FV = 10812.02$