Fraud Investigators Incorporated operates a fraud detection service.

On March $31,10$ customers were billed for detection services totaling $$30,000.$

On October $31,$ a customer balance of $$1,750$ from a prior year was determined to be uncollectible and was written off.

On December $15,$ a customer paid an old balance of $$850,$ which had been written off in a prior year.

On December $31,$ $$550$ of bad debts were estimated and recorded for the year.

Required:

$1.$ Prepare journal entries for each transaction above. $2.$ Complete the following table, indicating the amount and effect $(+$ for increase, $$ for decrease, and NE for no effect$)$ of each transaction. Ignore income taxes. Transaction $,$Net Receivables $,$Net Sales, Income From Operations

a$.$

b$.$

c$.$

d$.$