nalyzing Inventories with Quarterly Data and LIFO Liquidation

The inventory footnote from The Dow Chemical Company's first quarter 2019 SEC report follows. The company also reports cost of goods sold for Q1 of 2019 of $11,778 million.

Inventories, in millionsMar. 31, 2019Dec. 31, 2018Finished goods$5,703$5,640Work in process2,2392,214Raw materials940941Supplies891880Total$9,773$9,675Adjustment of inventories to a LIFO basis(292)(415)Total inventories$9,508$9,260

Average inventory days?