Cullumber Company reported these income statement data for a 2-year period. Cullumber Company uses a periodic inventory system. The inventories at January 1,2024, and December 31,2025, are correct. However, the ending inventory at December 31,2024 , is overstated by $7,920. What is the cumulative effect of the imventory error on total gross profit for the 2 years? (Do not lecve any answer field Bank Enter ofor amounts) The cumulative effect on total gross profit for the two years is $