1. After tasting three different brands of Ammonia-Betel Nut Ice Cream, 100 tasters are asked to pick their favorite. The table below shows the number of tasters who prefer each type.
Dr. Big Fingers Uncle Stain Scary Facebook Friend
39 27 34
Looks like Uncle Stain is a loser. What does your Chi-Squared analysis tell you?
a) What kind of Chi-Squared test do you perform?
b) How many degrees of freedom?
c) What do you conclude?
2. These data are from the fabled HUMC study of chemical abuse: The frequencies represent numbers of individuals who claim to have abuse "problems" with either alcohol or marijuana
Alcohol 18 12
Marijuana 9 24
a) What test (be specific!) can we conduct to determine if, in this sample, men and women have different abuse patterns?
b) Conduct the test and draw your conclusions-be sure to include an effect size statistic.
3. Using these same data, test Professor Anandamide's theory that, because of hormonal differences, men are twice as likely to abuse marijuana as they are to abuse alcohol; and women are twice as likely to abuse alcohol as they are to abuse marijuana.
a) Do the test and draw your conclusions.
b) Which effect size statistic (if it could be calculated via SPSS) would serve as an additional test of the theoretical predictions?
4. In this study of rates of cancer in mice, we expect that brown mice develop tumors
three times more often than do white mice or black mice. These are the observed instances of cancerous tumors in the mice:
Brown White Black
Instances of Tumor: 100 65 50
a) What test (be specific) do we conduct with these data?
b) What are the expected frequencies per cell?
b) What do we conclude about our samples of mice and cancer?
5. For 2 points extra credit: There is a really hilarious neuropsychological joke in this exam. What is it? Are you still laughing?
The solution provides step by step method for the calculation of Chi square test statistic . Formula for the calculation and Interpretations of the results are also included.