Flounder Windows manufactures and sells custom storm windows for three-season porches. Flounder also provides installation service for the windows. The installation process does not involve changes in the windows, so this service can be performed by other vendors. Flounder enters into the following contract on July 1, 2020, with a local homeowner. The customer purchases windows for a price of $2,520 and chooses Flounder to do the installation. Flounder charges the same price for the windows irrespective of whether it does the installation or not. The customer pays Flounder $2,050 (which equals the standalone selling price of the windows, which have a cost of $1,110) upon delivery and the remaining balance upon installation of the windows. The windows are delivered on September 1, 2020, Flounder completes installation on October 15, 2020, and the customer pays the balance due. Prepare the journal entries.