Averaging columns using lookups

G'day guys,

Back again,

This time I'm struggling to figure out, how I can average data based upon the selection of a month.

I need to average the data as a YTD and also show monthly data from the second spreadsheet..Its the YTD thats getting me stuck.

Do is use a SumIf /Countif or is there another solution?

Can some-one point me in the correct direction?

You asked a virtually identical question yesterday I believe ?

http://www.excelforum.com/excel-prog...g-lookups.html

If memory serves I gave you a SUMIF to calculate the YTD aggregate - if you wish to obtain the Average for this value divide the aggregate by: MONTH($B$1)

*assumes a) calendar year b) each "actual" period will have a value (ie no prior months are to be discounted from the average)