How to back into a weighted average?

[questionking]

[TABLE="width: 1615"]
<tbody>[TR]
[TD]I need help calculating a weighted average rate for a specific value. I know value 226 has a weighted average of 0.33920. How would I calculate this, given the criteria below? Thanks in advance for your help, it is much appreciated.

[TABLE="width: 139"]
<colgroup><col width="77" style="width: 58pt; mso-width-source: userset; mso-width-alt: 2816;"> <col width="108" style="width: 81pt; mso-width-source: userset; mso-width-alt: 3949;"> <tbody>[TR]
[TD="class: xl69, width: 77, bgcolor: transparent"] 130 [/TD]
[TD="class: xl70, width: 108, bgcolor: transparent, align: right"]0.15000%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 463 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.17245%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 273 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.25000%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 1,149 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.28097%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 571 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.32188%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 703 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.39686%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 82 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.40522%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 50 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.65000%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 96 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]0.81901%[/TD]
[/TR]
[TR]
[TD="class: xl69, bgcolor: transparent"] 174 [/TD]
[TD="class: xl70, bgcolor: transparent, align: right"]1.28639%[/TD]
[/TR]
[TR]
[TD="class: xl71, bgcolor: transparent"] 226 [/TD]
[TD="class: xl72, bgcolor: transparent"] [/TD]
[/TR]
[TR]
[TD="class: xl73, bgcolor: transparent"] 3,916 [/TD]
[TD="class: xl74, bgcolor: transparent, align: right"]0.35689%[/TD]
[/TR]
</tbody>[/TABLE]
[/TD]
[/TR]
</tbody><colgroup><col></colgroup>[/TABLE]

 

[RoryA]

Welcome to the forum.

Assuming that data is in A1:B12 and that the data means what I think it does, you would use:

=((B12*A12)-SUMPRODUCT(A1:A10,B1:B10))/A11

 

[questionking]

Thank you, that worked and checks out. Much appreciated!