STA429/1007 Assignment 8

Quiz on Friday March 16th at 12:10 p.m.

The file birdlung.dat has these variables:

1. Lung Cancer 1=Yes, 0=No
2. Sex 1=Female, 0=Male
3. Socioeconomic Status 1=High, 0=Low
4. Birdkeeping 1=Yes, 0=No
5. Age  
6. Years smoked  
7. Cigarettes per day  

Do a logistic regression, with lung cancer as the dependent variable. Carry out Wald tests to answer the following questions.

  1. Controlling for all the other variables, are the two smoking variables significantly related to having lung cancer at α=0.05? Test them simultaneously.
    1. Answer the question YES or NO.
    2. What is the numerical value of the test statistic? The answer is a number.
    3. What is the p-value? The answer is a number.
    4. Do you reject the null hypothesis? Answer Yes or No. Are the results statistically significant? Answer Yes or No.
  2. Controlling for all the other variables, are the sex and socioeconomic status significantly related to having lung cancer at α=0.05? Test them simultaneously.
    1. Answer the question YES or NO.
    2. What is the numerical value of the test statistic? The answer is a number.
    3. What is the p-value? The answer is a number.
    4. Do you reject the null hypothesis? Answer Yes or No. Are the results statistically significant? Answer Yes or No.
  3. Controlling for all other variables, is birdkeeping significantly related to the chance of getting lung cancer at α=0.05? This test is part of the default output.
    1. Answer the question YES or NO.
    2. What is the numerical value of the test statistic? The answer is a number.
    3. What is the p-value? The answer is a number.
    4. Do you reject the null hypothesis? Answer Yes or No. Are the results statistically significant? Answer Yes or No.
    5. The estimated odds of lung cancer are ____ times as great if you are a birdkeeper.
    6. In plain, non-statistical language, what do you conclude? Say something about lung cancer and keeping birds.