Fraud Investigators Incorporated operates a fraud detection service. a. On March 31, 10 customers were billed for detection services totaling $33,000. b. On October 31, a customer balance of $1,900 from a prior year was determined to be uncollectible and was written off. c. On December 15 , a customer paid an old balance of $820, which had been written off in a prior year. d. On December 31, $580 of bad debts were estimated and recorded for the year. 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