The unadjusted cash account balance for a company at December 31,2009 is $15,926. The bank statement showed a balance of $20,700 on this same date. The following information is available:

Bank Service Charge $ 6

NSF check from customer $ 324

Deposit in transit $ 1,576

In addition, two other items were discovered:

• Check #433 for the purchase of inventory was written correctly and paid by the bank correctly for $463, but was recorded on the books at $643.

• Outstanding checks at the end of November were $3,500;checks written by the company during December were $60,000; checks cleared by the bank during December were $57,000.

What is the true cash balance at December 31, 2009?