Chi-Squared Test Expectations
There are three tests that you need to be familiar with tomorrow - Goodness of Fit, Test of Independence, and Test of Homogeneity
For each test know how to:
1) Define/state null & alternative hypothesis
2) Know & check conditions
3) Find expected count
4) Calculate chi-squared test statistic
5) Calculate the degrees of freedom
6) Calculate the p-value using the TI-83
7) State the conclusion in the context of the problem. In other words, your conclusion should be similar to:
"I calculated a p-value of #. This p-value less than our assumed (or stated - if given) significance level of 0.05. Therefore, we reject the null hypothesis as the data supports the claim that ... whatever alternative hypothesis is .... "
OR
"I calculated a p-value of #. This p-value is more than our assumed (or stated - if given) significance level of 0.05. Therefore, we fail to reject the null hypothesis as the data fails to support the claim that ... whatever alternative hypothesis is .... "
NOTES:
* For Goodness of Fit - review problems here
* Click here for some chapter 13 questions from book with solutions - you need to scroll down to the bottom to get to chapter 13 questions
* Know the difference between the Test of Independence & Test of Homogeneity - Also know how the null & alternative Hypothesis differ as well as conclusions
Below are data for a Test of Homogeneity (there are two different populations - this is a medical study - one group took a new drug, another population took a placebo):We calculate a p-value of #. This p-value less than our assumed (or stated) significance level of 0.05. Therefore, we reject the null hypothesis as
Below are data for a Test of Homogeneity (there are two different populations - this is a medical study - one group took a new drug, another population took a placebo (a pill that has no effect) ):
For each test know how to:
1) Define/state null & alternative hypothesis
2) Know & check conditions
3) Find expected count
4) Calculate chi-squared test statistic
5) Calculate the degrees of freedom
6) Calculate the p-value using the TI-83
7) State the conclusion in the context of the problem. In other words, your conclusion should be similar to:
"I calculated a p-value of #. This p-value less than our assumed (or stated - if given) significance level of 0.05. Therefore, we reject the null hypothesis as the data supports the claim that ... whatever alternative hypothesis is .... "
OR
"I calculated a p-value of #. This p-value is more than our assumed (or stated - if given) significance level of 0.05. Therefore, we fail to reject the null hypothesis as the data fails to support the claim that ... whatever alternative hypothesis is .... "
NOTES:
* For Goodness of Fit - review problems here
* Click here for some chapter 13 questions from book with solutions - you need to scroll down to the bottom to get to chapter 13 questions
* Know the difference between the Test of Independence & Test of Homogeneity - Also know how the null & alternative Hypothesis differ as well as conclusions
Below are data for a Test of Homogeneity (there are two different populations - this is a medical study - one group took a new drug, another population took a placebo):We calculate a p-value of #. This p-value less than our assumed (or stated) significance level of 0.05. Therefore, we reject the null hypothesis as
Below are data for a Test of Homogeneity (there are two different populations - this is a medical study - one group took a new drug, another population took a placebo (a pill that has no effect) ):
From the table provided above, one should be able to calculate all the numbers below: