Answer:
$3900
Step-by-step explanation:
Calculation to determine the ending balance of the allowance account after the year-end adjustment
Balance in allowance for uncollectible account$ 900
Add Bad debts during the period $3,000
($75,000*4%)
Ending Balance in allowance for uncollectible account$ 3,900
($900+$3,000)
Therefore the ending balance of the allowance account after the year-end adjustment is $3900