) Carbon Drill company offers model A100 which is a free-standing precision industrial drill, plus installation to the customer's power source, for a total price of $1,900. On a standalone basis, the drill sells for $1,600(cost $940), and Carbon drill estimates that the fair value of the installation service(based on cost-plus estimation) is @400. Carbon drill signed a contract for 10 model A100s on May 30, 2019. On the date, the customer paid $1,600 per contract, with the remainder to be paid upon installation. The drill were delivered on Jun 30th and installed on July 15, 2019. Prepare journal entries for Custom drill relating to these contracts and indicate the date of entries.