Data - 2-Sample Poisson Rate
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You can enter the sample data in raw, frequency, or summarized form. Only raw and frequency data use a Minitab worksheet, and their data must consist of nonnegative integers. Minitab excludes missing values from all computations.

Raw data

All values from each sample are present in a column. If you want to enter raw data, do one of the following:

·    Enter data from each sample in a separate column (unstacked data).

·    Enter data from both samples into a single column (stacked data) with a separate column of subscripts identifying from which sample each item originates.

 Here are two ways of entering the same raw data:

Unstacked raw data

 

 

 

Stacked raw data

Defects A

Defects B

 

 

 

Defects

Subscripts

4

2

 

 

 

4

A

2

5

 

 

 

2

A

0

1

 

 

 

0

A

4

2

 

 

 

4

A

1

2

 

 

 

1

A

 

3

 

 

 

2

B

 

5

 

 

 

5

B

 

 

 

 

 

1

B

 

 

 

 

 

2

B

 

 

 

 

 

2

B

 

 

 

 

 

3

B

 

 

 

 

 

5

B

Frequency data

For each sample, unique observations exist in a single column, and their corresponding frequencies exist in a separate column. If you want to enter frequency data, do one of the following:

·    Enter unique values from each sample in a separate column (unstacked data), and enter their frequencies in two more distinct columns.

·    Enter unique values for each sample in a single column, enter subscripts identifying the sample of origin in a second column, and enter frequencies for each unique value in a third column.

Here are two ways of entering the above data in frequency format:

Unstacked frequency data

 

 

 

Stacked frequency data

Defects A

Defects B

Frequency A

Frequency B

 

 

 

Defects

Subscripts

Frequencies

0

1

1

1

 

 

 

0

A

1

1

2

1

3

 

 

 

1

A

1

2

3

1

1

 

 

 

2

A

1

4

5

2

2

 

 

 

4

A

2

 

 

 

 

 

 

 

1

B

1

 

 

 

 

 

 

 

2

B

3

 

 

 

 

 

 

 

3

B

1

 

 

 

 

 

 

 

5

B

2

Summarized data

Enter the sample size and the number of occurrences for each sample directly in the 2-Sample Poisson Rate dialog box.

To input the above data in summarized form, do the following:

1    Choose Summarized data.

2    In First, enter 5 (the sum of the Frequency A column) for Sample size and enter 11 (the sum of the unstacked Defects A column) for Total occurrences.

3    In Second, enter 7 (the sum of the Frequency B column) for Sample size and enter 20 (the sum of the unstacked Defects B column) for Total occurrences.