Calculate a dynamic average from a table in excel

Question

I have this table of currency rates:

I would like to create a formula that receives the begin date and end date + currency, and in return will calculate the average for every month inside the range.

For example, if the currency is GBP, begin date is 15/09/2015 and end date is 20/11/2015, I would like to calculate averages for 30/09/2015 + 31/10/2015 + 30/11/2015.

I tried to solve it with a simple Average + Vlookup + Match functions, but it wouldn't get me the range of cells but only the edges of the range. I also thought of using AverageIF function, but I'm not sure how to combine between the criterias of date and currency.

Can you think of an easy way to solve that?

Answer 1

I suggest using an index/match to get a reference to the beginning of the range of currencies then another one to get the end of the range and combining them like this:-

=AVERAGE(INDEX($B$2:$H$10,MATCH(D13,A$2:A$10,0),MATCH(1,(MONTH(E13)=MONTH($B$1:$H$1))*(YEAR(E13)=YEAR($B$1:$H$1)),0)):
INDEX($B$2:$H$10,MATCH(D13,A$2:A$10,0),MATCH(1,(MONTH(F13)=MONTH($B$1:$H$1))*(YEAR(F13)=YEAR($B$1:$H$1)),0))
)

Where the currency name is in D13, start date in E13 and end date in F13, and the table is in A1:H10.

Result: 1.5203

Must be entered as an array formula using Ctrl Shift Enter

Answer 2

Found a way to solve this, by using the AVERAGEIF function. Enjoy, and thanks for helping!