Chi-Square

Test of Homogeniety

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

Listed in terms of Rows X Columns

Df = (#Rows -1) (#Columns – 1)

Expected Value = row sum column sum

grand total

Test for Homogeniety

Test to see if proportions are the same

: Proportions are the same

: At least one proportion is differento

A

H

H

Test of Homogeniety

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 300 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

Worksheet