Exercise 18-9 Wildhorse Marina has 300 available slips that rent for $700 per season. Payments must be made in full by the start of the boating season, April 1, 2018. The boating season ends October 31, and the marina has a December 31 year-end. Slips for future seasons may be reserved if paid for by December 31, 2018. Under a new policy, if payment for 2019 season slips is made by December 31, 2018, a 6% discount is allowed. If payment for 2020 season slips is made by December 31, 2018, renters get a 17% discount (this promotion hopefully will provide cash flow for major dock repairs). On December 31, 2017, all 300 slips for the 2018 season were rented at full price. On December 31, 2018, 198 slips were reserved and paid for the 2019 boating season, and 72 slips were reserved and paid for the 2020 boating season. (a) Prepare the appropriate journal entries for December 31, 2017, and December 31, 2018. (Round answers to O decimal places, e.g. 5,275. Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No entry" for the account titles and enter O for the amounts.) Date Account Titles and Explanation Debit Credit (To record 2018 revenue.) (To record 2019 revenue.) (To record 2020 revenue.)