Consider a small 2-dimensional data set that has been classified by an expert into two groups (Group 1 is indicated by the solid circles, and Group 2 by solid squares). Suppose we wish to construct a decision tree classification of the data by dividing the region shown into four cells. 11 10 9 8 7 6 5 4 3 2 1 O 1 2 3 4 5 6 7 (a) Using the information theory based analysis, form the two level decision tree for the data. Show your calculations, and mark the decision boundaries in the chart above.