Microsoft Office Tutorials and References

In Depth Information

**Generating random numbers**

The parameters shown directly below the Distribution list change depending on the

type of distribution you select. As Figure 17-13 shows, when you select Uniform in

the Distribution list, you can specify the beginning and ending points of the

distribution in the Between and And text boxes.

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Figure 17-13
The Parameters area in the Random Number Generation dialog box

changes to reflect the distribution type you select.

Distributing random numbers uniformly

This option asks you to specify two numbers between which (and including) to generate a

set of random numbers. It works much the same way as the RANDBETWEEN function,

generating an evenly distributed set of real numbers. You can use this option as a more

convenient alternative to RAND if you want endpoints other than 0 and 1 or if you want sets of

numbers to be based on the same seed value.

Distributing random numbers normally

Normal distribution has the following characteristics:

One particular value, the mean, is more likely to occur than any other value.

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Values greater than the mean are as likely to occur as values less than it.

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Values close to the mean are more likely to occur than values distant from the mean.

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To generate normally distributed random numbers, you specify two parameters: the mean

and the standard deviation. The standard deviation is the average absolute difference

between the random numbers and the mean. (Approximately 68 percent of the values in a

normal distribution fall within one standard deviation of the mean.)