## Poisson distribution - Is there a Test for normality on it?

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Frequent Contributor
Posts: 105

# Poisson distribution - Is there a Test for normality on it?

Hi there:

I am looking for any test to evaluate the normality for a data set in Possion..

Thanks

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Solution
‎01-07-2016 02:00 PM
SAS Super FREQ
Posts: 3,841

## Re: Poisson distribution - Is there a Test for normality on it?

Do you mean "Is there a test to determine whether data are Poisson distributed?"  (You can't check for "normality" unless you think the data are normally distributed.)

If so, the answer is yes. You can fit a Poisson distribution to the data and examine the goodness of fit statistics.

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Valued Guide
Posts: 684

## Re: Poisson distribution - Is there a Test for normality on it?

I don't understand the question. If the data are Poisson, then why test for normality? Maybe you are wondering if you counts are large enough that the Poisson is adequately approximated by a normal distribution? If so, then use PROC UNIVARIATE and look a the output for tests for normality.

proc univariate data=... normal;

var y;

run;

Solution
‎01-07-2016 02:00 PM
SAS Super FREQ
Posts: 3,841

## Re: Poisson distribution - Is there a Test for normality on it?

Do you mean "Is there a test to determine whether data are Poisson distributed?"  (You can't check for "normality" unless you think the data are normally distributed.)

If so, the answer is yes. You can fit a Poisson distribution to the data and examine the goodness of fit statistics.

☑ This topic is solved.