Putting observed values in one list and expected values in another is the setup for:

1. The statistic pairs each observed count with its expected counterpart. 2. To run the test, put the observed values, the data, into a first list. 3. Put the expected values, the values you expect if the null hypothesis is true, into a second list. 4. The calculator then works through the paired terms to produce the statistic. 5. A scatter plot would need two measurements per case rather than paired counts. _Source: OpenStax Introductory Statistics 2e (CC BY 4.0), Ch 11 'The Chi-Square Distribution', sections 11.1-11.5_