I'm have a problem explaining differences in avegages in a workbook created
in Excel 2003

If I use sub totals from the data menu I get the following 4 results using
the SUBTOTAL(1, xx:xx) and SUBTOTAL(101,xx:xx):

99.38
98.17
97.26
98.06


But if I use the the standard average formula, or I sum the range and divide
by a count of cells having values I get the following results:
Average formula 1: AVERAGE(xx:xx)
Average formula 2: SUM(xx:xx)/COUNT(xx:xx)

99.38
98.16
97.23
98.05

While the differences are fractional I've been asked to determine why
there's a difference. Any and all information will be greatly appreciated.

Thanks...
--
Kevin Backmann