Ch. 28 Chi-square test

332 Views

Download Presentation
## Ch. 28 Chi-square test

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**Ch. 28 Chi-square test**• Used when the data are frequencies (counts) or proportions for 2 or more groups. • Example 1**5. Calculate ((observed-expected)^2)**expected 6. Calculate Chi-square = sum of the values from step 5. The degrees of freedom = (# rows - 1)x(# columns – 1). Find the p-value using the Chi-square table. Activity: Titanic survival data**Null hypothesis: Class and survival are independent. In**other words, everyone had the same chance of survival. Use the bootstrap method to estimate the proportions in the box based on the observed data. Null hypothesis: The proportion of “yes” in every class is the same as the overall proportion = 38%.**Chi-square =**• P-value =