Corporation began 2018 with a balance in Accounts Receivable of $ 580 comma 000. Service​ revenue, all on​ account, for the year totaled $ 2 comma 400 comma 000. The company ended the year with a balance in Accounts Receivable of $ 550 comma 000. Ridgewood​'s ​bad-debt write-offs are nonexistent. How much cash did the company collect from customers in 2018​?.