N

#### Nadine

title.

I have a column of invoice numbers and multiple rows of data pertaining to

each one. So one invoice number could have 10 rows of data pertaining to it

so the invoice number will be repeated 10 times. Then on each line is the

time it took to receive the data so this number will be the same on all 10

lines. I have hundreds of rows of data but only a handful of invoice

numbers. I need to find the average of the days based on the unique count of

the invoice numbers. I already have my formula for the unique count but now

need one for the average when the invoice numbers are not in contiguous cells

down the column.

Example:

Col A Col B

Invoice # # Days

12345 11

12345 11

12345 11

98995 15

66438 37

12345 11

98995 15

12345 11

So there are 3 unique invoice numbers. How do I write the formula to find

the average number days it took to receive all three? I'm in Excel 2003.