“(a) In the use of a categorical variable with n possible values, explain the following:

1. Why only n – 1 binary variables are necessary

2. Why using n variables would be problematic

(b) Describe how logistic regression can be used as a classifier.

(c) Discuss how the ROC curve can be used to determine an appropriate threshold value for a classifier

(d) If the probability of an event occurring is 0.4, then

1. What is the odds ratio?

2. What is the log odds ratio?

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