Shore Co provides for doubtful accounts based on 4% of gross trade receivables.

The following data are available for 2016 

Credit sales during 2017                                                          5,500,000 

Bad debt expense                                                                         60,000 

Allowance for doubtful accounts 1/1/17 credit balance              10,000 

Customer accounts written off as uncollectible during 2017      30,000 

What is the balance in Allowance for Doubtful Accounts at December 31 2016.