I'm having some problems figuring out the formula that will take the average of a list of values that are within a date range. Example:
Date Total Time
1/1/2015 5
1/15/2015 10
2/1/2015 5
2/15/2015 10

And the table I want to produce would be:
Jan/1/2015 7.5
Feb/1/2015 7.5
Mar/1/2015 0

I want just one formula that computes the value 7.5 where that value is located in the 2nd table.