A business hired a repair service to overhaul its plumbing system. The repair service began work on September 15 and completed it on October 15. The business agreed to pay the service $4,000 when the work was completed. As of September 30, the work was 50% complete, and the business made an adjusting entry to accrue repair expense as of the end of September. On October 15, the work was completed, and the repair service was paid in full. Provide the journal entry for the cash payment on October 15.