Answer: The adjusting entry would be: Debit Bad debt expense $24,380; Credit Allowance for doubtful accounts $24,380.
Explanation: Since aging of the accounts receivable shows that 7% approximately of the outstanding receivable of $374,000 will be uncollectible. It then means $26,180 (7%*$374,000) will be uncollectible. Meanwhile, Tanning Company already has a credit balance of $1,800 in the allowance for doubtful accounts, therefore, an adjustment of $24,380 ($2,180 - $1,800) has to be made.