Building decision tree model for dataset in R

The main objective of this assignment is to build a classifier using machine learning techniques that can accurately tell us if the person has diabetes or not

Decision Tree model

a. Does the data need any preparation for this algorithm? What did you do? Why? 

b. Draw the tree and write at least two rules. 

c. What are the variables that best split the data in the first and second level of the tree? 

d. Evaluate the developed model using at least three different metrics.