S

#### Steve

carry out a caculation based on groups of data for example:

Fields as follows:

Column A Column B Column C

Date and Time Total Calc Field

A1 14 Aug 14:20 26 C1

A2 14 Aug 14:20 34 C2 etc

A3 14 Aug 14:20 15

A4 14 Aug 14:20 9

A5 14 Aug 14:20 7

A6 14 Aug 14:50 120

A7 14 Aug 14:50 100

A8 14 Aug 14:50 65

A9 14 Aug 14:50 32

A10 14 Aug 14:50 12

In essence what I would like to be able to do is as follows:

the forumla in the calc field will return the result of B1 divided by

the sum of B1:B5 (because the date and time ranges are the same in

A1:A5

In this example C1 would return 0.29 (2 decimal places)

B1 = 26 / Sum B1:B5 = 91 = 0.29

I would like to then copy the formula down the column so that the

answer to C2 would be B2 divided by the sum of B1:B5 and so on......

Therefore when I copy all the way down and calculate the spreadsheet

the results would be all the way to the bottom so that the formula

would be correctly populated and therefore the answer to C10 would be

C6 divided by the sum of C6:C10 with the result being 0.36

I hope that makes sense and thanks in advance for any help

Steve