At the beginning of $20$X$1,$ U$4$y Hospital reported Accounts Receivable $$11000$ and Allowance for Uncollectible Accounts $$1800($credit$).$ During $20$X$1,$ before recording the year$-$end adjusting entries, the Hospital recorded credit sales revenue $$16000$ and wrote off accounts receivable $$400.$ The following balance was reported on December $31,201,$ before any adjustment: Accounts Receivable $=$$$13000.$ The Hospital estimates uncollectible accounts based on an aging of accounts receivable as shown below.

$\backslash$table$[[$Age Group,$\backslash$table$[[$Amount$],[$Receivable$]],\backslash$table$[[$Estimated Percent$],[$Uncollectible$]]],[$Not yet due,$$,8,000,10\%$