Final answer:
In Excel, to identify the oldest date in a field, you use the "MIN" function, which finds the minimum value corresponding to the earliest date.
Step-by-step explanation:
To display a total row identifying the oldest date in a field in your table in Microsoft Excel, you would select the "MIN" function from the list. This function is designed to find the minimum value in a range of cells, which, when used with dates, will return the earliest date. Functions like "COUNT", "SUM", and "AVERAGE" are for different types of calculations: counting entries, summing numeric values, and calculating the average of numbers in a range respectively.