Formula to adjust for variable quantity

[gflory]

I would like help in creating the formula that would weigh a third number: Each month, I collect the following data. I would like to be able to create a weighed conversion rate:
..........Showings......Contracts.........Listings......Conversion Rate
Jan........4517..............135...............678..............3%
Feb.......4324...............127...............709..............3%
Mar.......6045...............208...............740..............3.5%

How do I adjust(weigh) the conversion rate with the change in number of listings?

Thanks

 

[Gerald Higgins]

So, are you saying we can ignore the "Showings" and "Contracts" data, and just calculate a weighted conversion rate, using the "Listings" as a weighting factor ?

If yes, then maybe this

=SUMPRODUCT(D2:D4,E2:E4)/SUM(D2:D4)

returns a value of 3.174%.

This assumes . . .
Listings are in the range D2:D4
Conversion Rate is in the range E2:E4
The Conversion rates are EXACTLY 3%, 3%, and 3.5% - I suspect that really they are not.

 

[gflory]

Maybe a solution would be to determine conversion rate per 100 showings.

The showings and contracts are the primary numbers; the listings is added in an attempt to weigh the results of contracts/showings.

Thanks for looking at this problem,

 

[Gerald Higgins]

OK . . . I'm not really clear what you are asking now.