Pronghorn Windows manufactures and sells custom storm windows for three-season porches. Pronghorn 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. Pronghorn enters into the following contract on July 1, 2020, with a local homeowner. The customer purchases windows for a price of $2,470 and chooses Pronghorn to do the installation. Pronghorn charges the same price for the windows irrespective of whether it does the installation or not. The customer pays Pronghorn $1,940 (which equals the standalone selling price of the windows, which have a cost of $1,050) upon delivery and the remaining balance upon installation of the windows. The windows are delivered on September 1, 2020, Pronghorn completes installation on October 15, 2020, and the customer pays the balance due.

Pronghorn estimates the standalone selling price of the installation based on an estimated cost of $450 plus a margin of 30% on cost. Prepare the journal entries for Pronghorn in 2020 for July 1, Sep 1, and Oct 15 2020.