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Pancreatic Cancer
Determine whether coffee consumption is associated with the incidence of pancreatic cancer. Survivors
Determine whether there is a difference in survival rate among classes aboard the Titanic. |
Pancreatic Cancer: Problem |
A case-control study was carried out to investigate the existence of a relationship between coffee consumption and pancreatic cancer. The data provided is for male subjects, with Outcome as a categorical variable representing whether or not a subject had cancer, and DailyCoffee as a continuous variable representing the daily coffee consumption of a subject.
Using the likelihood ratio chi-square test, determine whether the data indicates an association between coffee consumption and incidence of pancreatic cancer. Give the chi-square test statistic and the p-value for the test. |
SAS Institute Inc.
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Pancreatic Cancer: Sample Data | |
The Coffee data set contains data about coffee consumption by individuals with and without pancreatic cancer. These are the variables in the data set: Name | Type | Description | | Outcome | char | indicator of whether individual is a case (pancreatic cancer) or a control (no cancer) | | DailyCoffee | num | amount of coffee drunk (0 for none, 1.5 for 1-2 cups per day, 3.5 for 3-4 cups per day, or 5.5 for 5 or more cups per day) | | AnyCoffee | char | coded value: if DailyCoffee=0, "No coffee"; otherwise "Some coffee" | |
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Source of Data
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This data is sample data from SAS Institute Inc. |
Pancreatic Cancer: Solution |
The value of the likelihood ratio chi-square statistic is 7.6195, with a p-value of 0.0546, which is not significant at the α = 0.05 level. However, at a significance level of α = 0.10, you could say that the data gives sufficient evidence of an association between coffee consumption and incidence of pancreatic cancer. |
Survivors: Problem |
Information was gathered on the passengers of the RMS Titanic and recorded in a dataset. The four variables represent the class (first, second, third, and crew), age, sex, and survival status (yes or no) for each passenger. Test the hypothesis that there is no difference in the survival rate among classes by using the likelihood ratio chi-square test with a significance level of α = 0.01. |
Lee Creighton (modified by Paris Faison)
SAS Institute Inc.
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Survivors: Sample Data | |
The Titanic data set contains information on the passengers of the RMS Titanic including class level, age, sex, and survival status. These are the variables in the data set: Name | Type | Description | | Class | char | class level of passenger (first, second, third, or crew) | | Age | char | age classification of passenger (adult or child) | | Sex | char | sex (male or female) | | Survived | char | survival status (yes or no) | |
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Source of Data
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Sall, J., Creighton, L., & Lehman, A. (2006). JMP Start Statistics, Third Edition. Cary, NC: SAS Institute Inc. |
Survivors: Solution |
Based on output from the FREQ procedure in SAS, we find that the value of the likelihood ratio chi square statistic is 180.9014, and the p-value for the test is found to be < 0.0001, which is significant at the α = 0.01 level. Hence, we can say that there is very strong evidence that there is a difference in the survival rate among classes who were aboard the RMS Titanic. |
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