At the beginning of January of the current year, Thomas Law Center's ledger reflected a normal balance of $52,200 for accounts receivable. During January, the company collected $15,000 from customers on account and provided additional services to customers on account totaling $12,600. Additionally, during January one customer paid Thomas $5,100 for services to be provided in the future. At the end of January, the balance in the accounts receivable account should be