Table 6.17, refers to the effectiveness of immediately injected or 1 hour-de1ayed penicillin in protecting rabbits
Question:
Table 6.17, refers to the effectiveness of immediately injected or 1 ½ hour-de1ayed penicillin in protecting rabbits against lethal injection with β-hemolytic streptococci.
a. Let X = delay, Y = whether cured, and Z = penicillin level. Fit the logit model (6.4). Argue that the pattern of 0 cell counts suggests that (with no intercept) β̂IZ = – ∞ and β̂5Z = ∞. What does your software report?
b. Using the Logit model, conduct the likelihood-ratio test of XY conditional independence. Interpret.
c. Test XY conditional independence using the Cochran – Mantel – Haenszel test. Interpret.
d. Estimate the XY conditional odds ratio using (i) ML with the logit model, and (ii) the Mantel – Haenszel estimate. Interpret.
e. The small cell counts make large-sample analyses questionnable.
Conduct small-sample inference, and interpret.
Table 6.17:
Step by Step Answer:
a The logit model 64 is given by the equation logitPY 1 0 1X 2Z The pattern of 0 cell counts suggests that with no intercept 1Z and 2Z This means that ...View the full answer
