Estimating Bad Debts from Receivables Balances

please help me to solve problem no 3. I already input my answer into my accounting lab but the answer is wrong.

Estimating Bad Debts from Receivables Balances The following information is extracted from Shelton Corporation's accounting records at the beginning of 2013: Accounts Receivable $64,000 Allowance for Doubtful Accounts 900 (credit) During 2013, sales on credit amounted to $600,000, $558,000 was collected on outstanding receivables and $2,500 of receivables were written off as uncollectible. On December 31, 2013, Shelton estimates its bad debts to be 5% of the outstanding gross accounts receivable balance. 1. Prepare the journal entry necessary to record Shelton's estimate of bad debt expense for 2013. Dec. 31 Bad Debt Expense 6775 Allowance for Doubtful Accounts 6775 2. Prepare the Accounts Receivable section of Shelton's December 31, 2013 balance sheet. Dec. 31 Accounts receivable 103500 Allowance for Doubtful Accounts 5175 Net accounts receivable 98325 3. Compute Shelton's receivables turnover. If required, round your answer to one decimal place. Receivable Turnover Ratio = Net Credit sales / Average net Receivables 600,000/98,325 = 6.1 (according to my accounting lab my answer is wrong) 4. If Shelton Company uses IFRS, what might be the heading for the accounts receivable section in Requirement 2