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10.1 CHI-SQUARE: TESTS OF
INDEPENDENCE AND
HOMOGENEITY
Part 2: Tests of Homogeneity
Tests of Homogeneity
   Homogeneous:     of the same structure or
                     composed of similar parts

   When we perform a test of homogeneity, we
    use a contingency table and the chi-square
    distribution to determine whether several
    populations share the same proportions of
    distinct categories.

   A test of homogeneity tests the claim that
    different populations share the same proportions
    of specified characteristics.
Tests of Independence VS Tests of Homogeneity
How to Test for Homogeneity of Populations






                       Note: when we reject the null
                       hypothesis, we do not know which
                       proportions differ among the
                       populations, we only know that the
                       populations differ in some of the
                       proportions sharing a characteristic.
Example: Test for Homogeneity
Tim is doing a research project involving pet
preferences among students at his college. He took
random samples of 300 female and 250 male students.
Each sample member responded to the survey question
If you could own only one pet, what kind would you
choose? The possible responses were: dog, cat,
other pet,
no pet. The results of the study follow.




                         Pet Preference


Does the same proportion of males as females prefer
each type of pet? Use a 1% level of significance. Well
answer this question in several steps

More Related Content

10.1 part2

  • 1. 10.1 CHI-SQUARE: TESTS OF INDEPENDENCE AND HOMOGENEITY Part 2: Tests of Homogeneity
  • 2. Tests of Homogeneity Homogeneous: of the same structure or composed of similar parts When we perform a test of homogeneity, we use a contingency table and the chi-square distribution to determine whether several populations share the same proportions of distinct categories. A test of homogeneity tests the claim that different populations share the same proportions of specified characteristics.
  • 3. Tests of Independence VS Tests of Homogeneity
  • 4. How to Test for Homogeneity of Populations Note: when we reject the null hypothesis, we do not know which proportions differ among the populations, we only know that the populations differ in some of the proportions sharing a characteristic.
  • 5. Example: Test for Homogeneity Tim is doing a research project involving pet preferences among students at his college. He took random samples of 300 female and 250 male students. Each sample member responded to the survey question If you could own only one pet, what kind would you choose? The possible responses were: dog, cat, other pet, no pet. The results of the study follow. Pet Preference Does the same proportion of males as females prefer each type of pet? Use a 1% level of significance. Well answer this question in several steps