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 H o : Proportions are the same H A : At least one proportion is different 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