Answer:
$523,600 on the 2021 retained earnings statement
Step-by-step explanation:
Gross profit of 2019 under percentage-of- $889,000 
completion method 
Add: Gross profit of 2020 under percentage $940,000 
-of-completion method 
Less: Gross profit of 2019 under completed- ($466,000 ) 
contract method 
Less: Gross profit of 2020 under completed- ($615,000)
contract method  
 $748,000
Less: Tax ($748,000*30%) $224,400
 $523,600