Final answer:
Eli is using the MAX function in Excel to find the maximum value within a specified range, which is the largest number between cells C4 and C15. This value could correspond to an element's contribution to a molecular mass in the context provided.
Step-by-step explanation:
Eli is looking for the highest value in the range C4:C15 in his Excel spreadsheet. The MAX function in Excel is used to find the maximum value in a range of cells. So, when Eli writes MAX(C4:C15), he's asking the spreadsheet to calculate and return the largest number found between cells C4 and C15. This could be a quantity related to the molecular mass table mentioned, where each cell within that range might represent a subtotal for a certain element's contribution to the molecular mass of a compound, similar to what is described in the provided table context.