Karl Pearsons ChiSquared Test Overall Objective The objective

Karl Pearson’s Chi-Squared Test Overall Objective: The objective of the Chi-Squared test is to determine if the variation in your data is due to chance, or one of the variables you are testing. This can be achieved by determining whether or not the chi squared value exceeds or does not exceed your critical value. This will indicate whether or not you need to reject your null hypothesis. Null Hypothesis: There is no Statistical difference between the observed and expected frequencies. 1. Use the formula 2 2 x = Σ (Oi – Ei) Ei Oi = Observed Value Ei = Expected Value 2. Degree of Freedom = # of possible outcomes - 1 3. Critcal Value: Any number on the chart next to the DF value and under one of the given row values (0. 05 is the most commonly used) **After the Formula is carried out , the Chi Squared Value is found, the degree of freedom is established, and a critcal value is determined, MOVE TO STEP 4!!!! 2 x < 4 a. If the critical value determined then you accept the Null Hypothesis 2 4 b. If x > the critical value determined then you reject the null hypothesis. DF 1 2 3 4 5 6 7 8 9 0. 10 2. 706 4. 605 6. 251 7. 779 9. 236 10. 645 12. 017 13. 362 14. 684 0. 05 3. 841 5. 991 7. 815 9. 488 11. 070 12. 592 14. 067 15. 507 16. 919 0. 025 5. 024 7. 378 9. 348 11. 143 12. 833 14. 449 16. 013 17. 535 19. 023