Mary Beth Teoli, D$.$D$.$S$.,$ keeps her accounting records on the cash basis. During $20$X$1,$ she collected $$250,000$ in fees from her patients. At December $31,20$X$0,$ Dr$.$ Teoli had accounts receivable of $$27,000$ and no liability for deferred fee revenue. At December $31,20$X$1,$ she had accounts receivable of $$39,000$ and a liability for deferred fee revenue of $$3,000.$