Generating random numbers with normal distribution

问题:

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?

回答1:

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.

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

回答2:

IF you have excel 2007, you can use

=NORMSINV(RAND())*SD+MEAN

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

回答3:

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

回答4:

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.

回答5:

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

(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.

回答6:

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.

回答7:

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.