The accompanying data set contains three predictor variables (x₁, x₂, and x₃) and the target variable (y). Partition the data in the Exercise_9.18_Data worksheet to develop a naïve Bayes classification model where “Yes” denotes the positive or success class for y. Score the 10 new observations on the Exercise_9.18_Score worksheet. 

a. Report the accuracy, sensitivity, and specificity rates for the validation data set. 

b. Generate the decile-wise lift chart. What is the lift value of the leftmost bar? What does this value imply? 

c. Generate the ROC curve. What is the area under the ROC curve (or the AUC value)? 

d. Report the scoring results for the first three new observations.