Chi-Square
Test of Homogeneity
The following shows the results of 200 test
scores. Are the test scores normally distributed?
Score
Freq
50 - 59
19
59 - 68
61
68 - 77
82
77 - 86
34
86 - 95
4
%
Are your nuts evenly distributed?
nut
observed
Bazil
112
Cashew
183
Almonds
207
Hazelnut
71
Peanut
446
Contingency Table
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Listed in terms of Rows X Columns
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Df = (#Rows -1) (#Columns – 1)
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Expected Value =
row sum  column sum
grand total
Test for Homogeniety
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Test to see if proportions are the same
 H o : Proportions are the same
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 H A : At least one proportion is different
Test of Homogeniety
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State the hypotheses
Assumptions
Name of Test
Compute expected values
Find test statistic
Find p-value
Make Decision
State Conclusion
An advertising firm has decided to ask 92 customers at each of
three local shopping malls if they are willing to take part in a
market research survey. At a 1% significance level, can it be
concluded that the proportions of those who are willing to
participate are equal?
Mall A
Mall B
Mall C
Will Participate
52
45
36
Will Not Participate
40
47
56
Survey of 1st time fathers to see if there were in the delivery
room when their child was born. Are the proportions of
those in the delivery room the same at three local hospitals?
Hospital A
Hospital B
Hospital C
Present
66
60
56
Not Present
9
15
19
Let’s check our eye dominance! Is it the
same for boys & girls?
Homework
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Worksheet