Need help with manual solution method

(25Pts.) 1. Last year a dentist made the decision to keep some existing X-ray diagnosis equipment for another year (chis year) instead of purchasing a new X-ray unit for $15,000. Using "one additional year replacement analysis" and the data below that is now known, determine whether the dentist made the correct economic decision at an investment rate of 18% per year. (Lecture 12-N4wcwAAT-W6'NG 6wue) Existing Equipment for Last Year Trade-in Value last year Market Value this year $2.0 Operating Cost last year$500 $3,000 New Equipment if bought last year $15,000 10 yTs SV after 10 yrs $1,000 AOC $3,000