To complete parts D & E, we must populate the "Gallons of water..." columns (G and H).

Starting in column H "Gallons of Water (per shirt)", use the VLOOKUP function to start with the value from the "PRODUCT" column as an input and retrieve the appropriate related value from the "Gallons" column in the table at the top of the "Assumptions" worksheet. If done correctly, this (per shirt) number of gallons should appear in the "Gallons of Water (per shirt)" table for every batch (see screenshot below for the first few rows). (HINT: "Category" in column G also uses the VLOOKUP function, use that and Excel Help as needed)