Thrasher Construction Co. was contracted to construct a building for $995,000. The building is owned by the customer throughout the contract period. The contract provides for progress payments. Thrashers accounting year ends 31 December. Work began under the contract on 1 July 20X5, and was completed on 30 September 20X7. Construction activities are summarized below by year: 20X5 Construction costs incurred during the year, $183,600; estimated costs to complete, $642,600; progress billings during the yea