Calculating percentages per group

[Guest]

I have the following format in excel:
Column A Column B Column C
Books
Alpha 2
Bravo 8
Cars
Bravo 9
Charlie 11


I would like to add a Column D that calculates percentages of items in each group and looks like the following:

Column A Column B Column C Column
Books
Alpha 2 20%
Bravo 8 80%
Cars
Bravo 9 45%
Charlie 11 55%

I am not sure how to do this formula...it would probably have to differentiate groups by the blank cells between the numbers in Column C. Any ideas?

Thanks for any help you can provide.

 

[Frank Kabel]

Hi
first a question: Would it be possible for you to change your
spreadsheet layout. e.g.
- fill column A for all rows
- no blank rows in between?

This way you could use Excel's pivot tables to create such a report
without any problems 8and also formulas would be easier)

 

[Guest]

Yes, I could have it so it would look like:
Column A Column B Column C
Books Alpha 2
Books Bravo 8
Cars Bravo 9
Cars Charlie 11

 

[Frank Kabel]

Hi
the use a pivot table for your report. See:
http://www.cpearson.com/excel/pivots.htm
http://peltiertech.com/Excel/Pivots/pivotstart.htm
http://www.contextures.com/xlPivot02.html
http://www.ozgrid.com/Excel/excel-pivot-tables.htm