I have to make the following adjustment:

"Make any adjustments necessary to the Installation Inventory account for financial statement preparation. The opening installation inventory is $62,400 and the ending installation inventory is $43,200".

The company uses the PERIODIC INVENTORY SYSTEM, so I'm not able to just credit the installation inventory account and record it as an expense. I calculated my cost of goods sold which is $133,903.50. The periodic system doesn't allow you to take thefinal inventory figure, then compare it to the ledger value for the Inventory account, which has been kept up-to-date during the fiscal period.