18. $5,000 due today is to be paid instead by payments of $2,000 in 4 months and the balance in 9 months. Find the size of the last payment if interest is at 9% and the focal date is today. 19. Two payments of $1,200 each were due 30 and 60 days ago. They are to be paid off by two equal payments, one in 60 days and one in 90 days. If the focal date is 90 days from today and interest is at 12%, find the size of the payments