And the Magic Number is 3.841

Rory is working on his science fair project.  He’s getting an early start because it is a psychology experiment and he needs to subject at least 60 people to a questionnaire. In the meantime, dad is trying to relearn what he used to know about determining statistical significance in a dichotomous study using a binary response scale. Turns out, the study will employ a (simple) 2 x 2 contingency Chi-square analysis. Duh.

And remember . . . the critical value for determining statistical significance in a contingency Chi-square when df = 1 is . . . wait for it . . . 3.841.

Gotta pump up that N value. Can we get 80 instead of 60?

Useful links:

http://web.pdx.edu/~newsomj/da1/ho_chisq.pdf

https://www.uam.es/personal_pdi/ciencias/anabz/Prest/Trabajos/Critical_Values_of_the_Chi-Squared_Distribution.pdf

 

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