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I want to produce 100 random numbers with normal distribution (with µ=10, σ=7) and then draw a quantity diagram for these numbers.

How can I produce random numbers with a specific distribution in Excel 2010?

One more question:

When I produce, for example, 20 random numbers with RANDBETWEEN(Bottom,Top), the numbers change every time the sheet recalculates. How can I keep this from happening?

ZygD
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ha.M.ed
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    Use the Analysis ToolPak - [Random Number Generation](http://support.microsoft.com/kb/213930) –  Jun 05 '11 at 09:20

7 Answers7

100

Use the NORMINV function together with RAND():

=NORMINV(RAND(),10,7)

To keep your set of random values from changing, select all the values, copy them, and then paste (special) the values back into the same range.

Sample output (column A), 500 numbers generated with this formula:

enter image description here

Rory
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Excellll
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5

IF you have excel 2007, you can use

=NORMSINV(RAND())*SD+MEAN

Because there was a big change in 2010 about excel's function

Brian Mains
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JeeHyoung Kim
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As @osknows said in a comment above (rather than an answer which is why I am adding this), the Analysis Pack includes Random Number Generation functions (e.g. NORM.DIST, NORM.INV) to generate a set of numbers. A good summary link is at http://www.bettersolutions.com/excel/EUN147/YI231420881.htm.

studgeek
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Rand() does generate a uniform distribution of random numbers between 0 and 1, but the norminv (or norm.inv) function is taking the uniform distributed Rand() as an input to generate the normally distributed sample set.

Matthew Murphy
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About the recalculation:

You can keep your set of random values from changing every time you make an adjustment, by adjusting the automatic recalculation, to: manual recalculate. (Re)calculations are then only done when you press F9. Or shift F9.

See this link (though for older excel version than the current 2013) for some info about it: https://support.office.com/en-us/article/Change-formula-recalculation-iteration-or-precision-73fc7dac-91cf-4d36-86e8-67124f6bcce4.

cybork
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Take a loot at the Wikipedia article on random numbers as it talks about using sampling techniques. You can find the equation for your normal distribution by plugging into this one

pdf for normal distro

(equation via Wikipedia)

As for the second issue, go into Options under the circle Office icon, go to formulas, and change calculations to "Manual". That will maintain your sheet and not recalculate the formulas each time.

jonsca
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The numbers generated by

=NORMINV(RAND(),10,7)

are uniformally distributed. If you want the numbers to be normally distributed, you will have to write a function I guess.

Smit
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    That's 100% false. If you're not convinced, try generating 500 numbers with this formula and then look at the histogram of the numbers. – Excellll Jul 01 '16 at 15:10