It is july 1, and eduardo wants to purchase an engagement ring for his soon-to-be fiancée. he visits several jewelry stores and finds the perfect ring. the cost of the ring is $1,800. eduardo doesn't want to put the purchase on a credit card, so he decided to put the ring on layaway. since he needs the ring in 6 months so that he can propose on new year’s eve, he agrees to pay the store $300 per month. since eduardo knows exactly how much money he needs to pay each month, this is a(n) goal