Amazon Inc. reports the following accounts receivable at December 31, 2021 Estimated % Uncollectible Days Outstanding 0-30 31-60 61-120 Over 12e Amount $440,000 160,000 120,000 140,000 9% 18% During 2021. Amazon wrote off $20,000 in receivables and recovered $8,000 that had been written off in prior years. Amazon's December 31, 2020, allowance for uncollectible accounts was $50,000. Using the aging of accounts receivable method, what amount of allowance for doubtful accounts should Amazon report at December 31, 2021