Complete the following steps if your data follow a Poisson distribution.
- In Response, enter the column of Poisson data that you want to analyze. Poisson data contain counts, such as the number of defects per unit or sample. With Poisson data, Minitab compares the rate of occurrence for each sample to the overall rate. Each sample should have the same number of observations. The sample size must be large enough to ensure that the normal distribution adequately approximates the Poisson distribution because the decision limits are based on the normal distribution. The normal distribution is adequate when the mean is at least 5.
- Under Distribution of Data, select Poisson.
In this worksheet, Defects is the response. Each row represents the number of defects counted in samples of 50 cell phones. For example, the inspectors count 2 defects in the first sample of 50 cell phones and 4 defects in the second sample of 50 cell phones