AVERAGE BASED ON 2 CRITERIA

[aj]

I have a set of data on the entry and exit dates of a person. I have
calculated the number of days between two dates. I would now like to average
the number of days that fall in between two dates.
Example:
Enter Date Exit Date Number of days
1/12/09 1/13/09 1
1/19/09 1/23/09 4
1/26/09 1/30/09 3

I'd like the aver number of days between 1/12 and 1/19.

 

[Dave Peterson]

Maybe you just want:
=average(c2:C4)

But the average number of days between dates (to me) is just the number of days
between dates.

You could subtract them and format the cell with the formula as General.

You may want to subtract 1 or 2 if you don't want to include the end dates.