June 12, 2018 provide services to customers on account for $34,400. september 17, 2018 receive $19,500 from customers on account. december 31, 2018 estimate that 45% of accounts receivable at the end of the year will not be received. march 4, 2019 provide services to customers on account for $49,400. may 20, 2019 receive $10,000 from customers for services provided in 2018. july 2, 2019 write off the remaining amounts owed from services provided in 2018. october 19, 2019 receive $39,500 from customers for services provided in 2019. december 31, 2019 estimate that 45% of accounts receivable at the end of the year will not be received.