Answer:
$3900000
Step-by-step explanation:
The gross profit is the difference between the revenue earned during the year and the cost of sales. The percentage of completion method is one in which the revenue is recognized based on the cost incurred to date on the project.
Revenue to be recognized in 2021
= $15600000/($15600000 + $9600000) * $31500000
= $19500000
Though the billings for the year is lower, the difference may be recognized as unbilled receivable.
As such, the gross profit for the year
= $19500000 - $15600000
= $3900000