The balance in the prepaid insurance account, before adjustment at the end of the year, is $$22,500.$ Journalize the adjusting entry required under each of the following alternatives for determining the amount of the adjusting entry required under each of the following alternatives for determining the amount of the adjustment: $($a$)$ the amount of insurance expired during the year is $$18,000$; $($b$)$ the amount of unexpired insurance applicable to future periods is $$4,500$