Average based on 2 critera

Hi, I've had a really good look through previous posts and I'm so almost at my answer but it just doesn't work. So I am calling on greater knowledge!
I have attached an example. I need to populate Cell H3 with an average Capacity from Column E but I only need it to calculate those that match, in this case I & M from colums C&D which contain information stripped out form Column B
I have tried using this formula
AVERAGE(IF((C2:C350="I")*(D2:D350="M"),E2:E350))
and I've tried to enter as an array but it won't let me. Can anyone see where I am going wrong as I have wasted most of the day on this!!!

Also just to complicate things more after I have this working I will need to look at this based only on dates that have already passed. What amendments will I need to make to the formula to get it to look for dtaes in the past?
ThanksExample.xlsx

Thanks for your response
Strange- I've just entered the forumula into my example and it returns 0 which I am sure isn't right. Was going to upload the spreadsheet again but can't seem to do it

Example.xlsx
Figured out how to attach it

Originally Posted by daddylonglegs

Did you try AVERAGEIFS as Martin suggested, you don't need to "array enter" it

=AVERAGEIFS(E2:E350,C2:C350,"I",D2:D350,"M")

Not yet as I wans't sure how or whether I was in Excel 2007!!
Will go and try it now. Thanks

Thanks you so much that worked :-)
How would I manipulate that to look only for dates that are before today?

Thank you, it's now come at DIV/O) but I think that's to do with my figures. I'm almost there. Really appreciate your help. Thanks

Originally Posted by martindwilson

0.28482379
is the result array entered formula why are you not seeing that? how are you entering the array?

Ctrl+ Shift+ ENTER but it's not putting the {} signs in as it used to . I am in a different computer than the last time I tried to do it

Yup doing that, tried positioning cursor at end and selecting whole formula and trying it. I think tbh it's an issue with my computer as it's a wise box to a server and it has random issues like this!! Thanks for your help the Averageifs has worked just trying to get the dates sorted now. Oh well it's filled a day :-)