Jorgansen Lighting, Incorporated, manufactures heavy$-$duty street lighting systems for municipalities. The company uses variable costing for internal management reports and absorption costing for external reports to shareholders, creditors, and the government. The company has provided the following data:

Year $1$ Year $2$ Year $3$

Inventories

Beginning $($units$)210170190$

Ending $($units$)170190220$

Variable costing net operating income $ $300,000$ $ $279,000$ $ $260,000$

The company$$s fixed manufacturing overhead per unit was constant at $$560$ for all three years.