1. Chi Square Test of Homogeneity
Warm up 2/6
Work on the warm up!

2. Chi Square Test of Homogeneity
Now let’s say I am now given this table of information on what graduates from several colleges at one university are going to do post-grad.

3. Chi Square Test of Homogeneity
Here, we ask whether the post-grad choices made by students are the same for these four colleges.
We are going to test this using the chi-square test of homogeneity.

4. Chi Square Test of Homogeneity
Typical hypothesis test:
H0: variable has the same distribution across all populations HA: the variable DOES NOT have the same distribution across all populations
df = (rows – 1)(columns – 1) Requirements:  SAME!
Random Sample*
All counts ≥ 5
Less than 10% of population

5. Chi Square Test of Homogeneity
So, for our example:
H0: Students’ post-grad choices are distributed in the same way for all four colleges HA:  Students’ post-grad choices are NOT distributed in the same way for all four colleges
Check conditions and determine test
This is where it gets a little weird.. On your calculator: Hit 2nd - > x-1 (MATRIX) -> EDIT We have a table that is 3 rows x 4 columns

6. Chi Square Test of Homogeneity
Now let’s put in our values.

7. Chi Square Test of Homogeneity
Now let’s put in our values.
Then go to STAT -> TESTS -> C:

8. Chi Square Test of Homogeneity
Chi-square statistic = P-value = 5.82 x 10-10
The P-value is very small, so we reject the null hypothesis. There is evidence that suggests that the post-grad choices of students from these four colleges don’t have the same distribution.