Solution:
1% x $88,000 = $880
That's the noncollectable estimate
$88,000 - $880 = $87,120
That's the approximate amount to be collected.
Since $69,600 has already been collected, that leaves $17,520
[ $87,120 -$69,600= $17,520 ]
This is realized but not taken into account.
The amount of net realizable value of receivables on the December 31, Year 1 balance sheet would be: $17,520