<div>
C2 &nbsp; &nbsp; &nbsp;=1/B2/SUMPRODUCT(($A$2:$A$<wbr />31=A2)/$B$<wbr />2:$B$31)
</div>


retired

Ian Bell

<div>
Thanks Saqib, it works like a charm<br />
Ian
</div>


<div>
If a cell contains a zero in column B then the whole column (E) displays a divide by zero error, how can this be corrected ?<br />
Thanks
</div>


<div>
Thanks again Saqib, it takes a long time to calculate but I can run it overnight
</div>


<div>
How many rows do you have?<br />
<br />
What is the maximum length of a set? This may help speed it up.
</div>


<div>
160,000 rows and 78 columns would contain that formula you created.
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What is the maximum length of a data set who's sum needs to be 1?
</div>


<div>
That is the max length and width of the data set.
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<div>
In the given sheet in column A there are 4 data sets whose sum needs to be 1. What could be the maximum length of one of those 4 data sets?
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<div>
Oh I see. The maximum index range as I would understand it to be is 36 but that is very rare.<br />
The average would be around 10-12
</div>


<div>
See if this performs any faster<br />
<br />
=1/B2/ROUND(SUMPRODUCT((--<wbr />(OFFSET($A<wbr />$2,MAX(0,R<wbr />OW(A2)-40)<wbr />,0,80)=A2)<wbr />)/(OFFSET(<wbr />$B$2,MAX(0<wbr />,ROW(A2)-4<wbr />0),0,80)+0<wbr />.000000000<wbr />01)),2)
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<div>
Is &nbsp;-40 related to the 31 rows ? in which case if I have 159,600 rows I could use -160,000 ?<br />
What then is &nbsp;80 in the formula ? <br />
Thanks
</div>


<div>
The 40 is an additional margin for 36 as a maximum index range.
</div>


<div>
Okay, I think I said the same in a roundabout way.<br />
I still am curious about the 80 ?
</div>


<div>
All understood now and many thanks Saqib<br />
Ian
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<div>
<div class="content wysiwyg-content">
Hi,<br />
I would like one formula to sum probabilities to one within an Index Range.<br />
Please refer to attached sheet<br />
Many thanks<br />
Ian<a href="https://filedb.experts-exchange.com/incoming/2018/08_w35/1379172/Sum-Probabilities-to-one.xlsx" target="_blank" class="file-inline" title="sum probs (10 KB)"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><path d="M67.508 468.467c-58.005-58.013-58.016-151.92 0-209.943l225.011-225.04c44.643-44.645 117.279-44.645 161.92 0 44.743 44.749 44.753 117.186 0 161.944l-189.465 189.49c-31.41 31.413-82.518 31.412-113.926.001-31.479-31.482-31.49-82.453 0-113.944L311.51 110.491c4.687-4.687 12.286-4.687 16.972 0l16.967 16.971c4.685 4.686 4.685 12.283 0 16.969L184.983 304.917c-12.724 12.724-12.73 33.328 0 46.058 12.696 12.697 33.356 12.699 46.054-.001l189.465-189.489c25.987-25.989 25.994-68.06.001-94.056-25.931-25.934-68.119-25.932-94.049 0l-225.01 225.039c-39.249 39.252-39.258 102.795-.001 142.057 39.285 39.29 102.885 39.287 142.162-.028A739446.174 739446.174 0 0 1 439.497 238.49c4.686-4.687 12.282-4.684 16.969.004l16.967 16.971c4.685 4.686 4.689 12.279.004 16.965a755654.128 755654.128 0 0 0-195.881 195.996c-58.034 58.092-152.004 58.093-210.048.041z"/></svg>Sum-Probabilities-to-one.xlsx</a>
</div>
</div>


Sum-Probabilities-to-one.xlsx

Hi,
I would like one formula to sum probabilities to one within an Index Range.
Please refer to attached sheet
Many thanks
Ian

Formula to sum probabilities to one within an Index Range

A spreadsheet is an interactive computer application program for organization, analysis and storage of data in tabular form. Spreadsheets developed as computerized simulations of paper accounting worksheets. The program operates on data represented as cells of an array, organized in rows and columns. Each cell of the array may contain either numeric or text data, or the results of formulas that automatically calculate and display a value based on the contents of other cells.

Spreadsheets

Microsoft Excel topics include formulas, formatting, VBA macros and user-defined functions, and everything else related to the spreadsheet user interface, including error messages.

Microsoft Excel

Microsoft Office is an integrated suite of applications that includes Outlook, Word, Excel, Access, PowerPoint, Visio and InfoPath, along with a number of tools to assist in making the individual components work together. Coding within and between the projects is done in Visual Basic for Applications, known as VBA.