Generate Random Data

Overview | How to | Example

Overview

This procedure generates random data for the following distributions:

Chi-square distribution - used when outcomes are positive and such that X follows a normal distribution (where square of X then follows a chi-square)
Normal distribution - used when data follows a bell curve
F distribution - commonly used in test of variance
t distribution - similar to normal distribution with its tail spreading out wider
Uniform distribution - used to model data within a range of values and have an equal probabilities of occurrence
Bernoulli distribution - distibution with binary outcomes
Binomial distribution - based on probability of success given a specific number of trials
Hypergeometric distribution - used for permanent samples taken from small populations
Discrete distribution - user specified distribution using different values and its expected probabilities of occurrence
Integer distribution - user specified distribution with a range of integer values and each have an equal probabilities of occurrence
Poisson distribution - used when the probability of occurence is small
Beta distribution - used to model distribution of order statistics
Exponential distribution - used to time based data where failure rate is constant
Gamma distribution - used to model data that are positive and skewed
Lognormal distribution - commonly used to model reliability data and such that X follows a normal distribution (where LogX then follows Lognormal)
Triangular distribution - used when data is within a range and peaks at a value in between
Weibull distribution - commonly used to model failure times

How to

At the Excel Menu (For Excel 2007, go to Add-ins first)

Choose ProcessMA > Statistics > Generate Random Data
In Distribution, select the type of distribution you want to generate data from.
In No. of data points, enter the number of data points you want to generate per column.
In Output data in, select an existing available column to display the random data.

For Chi-square distribution

In Degrees of freedom, enter the number of degrees of freedom to define the Chi-square Distribution (Integer)

For Normal distribution

In Mean, enter the value to use as the center of the normal distribution (Numeric)
In Standard deviation, enter the value to use as the standard deviation of the Normal Distribution (Numeric, >0)

For F distribution

In Numerator DoF, enter the number of degrees of freedom for the effect (Positive integer)
In Denominator DoF, enter the number of degrees of freedom for the error (Positive integer)

For t distribution

In Degrees of freedom, enter the number of degrees of freedom to define the t Distribution (Positive integer)

For Uniform distribution

In Lower end-point, enter the value to define the minimum value for the Uniform Distribution (Numeric)
In Upper end-point, enter the value to define the maximum value for the Uniform Distribution (Numeric)

For Bernoulli distribution

In Probability of success, enter a value for the probability of success (between 0 and 1) to define the Bernoulli Distribution (Numeric, between 0 and 1)

For Binomial distribution

In Number of trials, enter the number of trials to define the Binomial Distribution (Positive integer)
In Probability of success, enter a value for probability of success (between 0 and 1) to define the Binomial Distribution (Numeric, between 0 and 1)

For Hypergeometric distribution

In population size, enter the population size (Positive integer)
In No. of successes in population, number of successes in the population. (Positive integer between 0 and the population size)
In Sample size, enter the sample size. (Positive integer between 0 and the population size)

For Discrete distribution

In Values, select the column containing the values you want to be included in the distribution
In Probability of values, select the column containing the probabilities that correspond to the discrete numbers in the Values

For Integer distribution

In Minimum value, enter the starting value (Integer)
In Maximum value, enter the ending value (Integer)

For Poisson distribution

In Mean, enter the mean value to define the Poisson Distribution. (Numeric, between 0 and 709)

For Beta distribution

In First shape parameter, enter a value for the first shape parameter to define the Beta Distribution (Numeric, >0)
In Second shape parameter, enter a value for the second shape parameter to define the Beta Distribution (Numeric, >0)

For Exponential distribution

In Mean, enter the mean value to define the Exponential Distribution (Numeric)

For Gamma distribution

In First shape parameter, enter a value for the first shape parameter to define the Gamma Distribution (Numeric, >0)
In Second shape parameter, enter a value for the second shape parameter to define the Gamma Distribution (Numeric, >0)

For Lognormal distribution

In Location, enter a value for the location to define the Lognormal Distribution (Numeric)
In Scale, enter a value for the scale to define the Lognormal Distribution (Numeric, >0)

For Triangular distribution

In Lower end-point, enter the value to define the minimum value for the Triangular Distribution (Numeric)
In Mode, enter the value to define the mode for the Triangular Distribution (Numeric)
In Upper end-point, enter the value to define the maximum value for the Triangular Distribution (Numeric)

For Weibull distribution

In First shape parameter, enter a value for the first shape parameter to define the Weibull Distribution (Numeric, >0)
In Second shape parameter, enter a value for the second shape parameter to define the Weibull Distribution (Numeric, >0)

Example

You want to generate 30 data data points from the Normal distribution with a mean of 10 and a standard deviation of 2.5. You want to store the data in Column A

Choose ProcessMA > Statistics > Generate Random Data
Complete the dialog box as shown in the figure below and click OK
The data will be stored in Column A of the current worksheet