NO.PZ201512020300000503
问题如下：
Which of the following machine learning techniques is most appropriate for executing Step 2:
选项：
A.K-Means Clustering
Principal Components Analysis (PCA)
Classification and Regression Trees (CART)
解释：
A is correct. K-Means clustering is an unsupervised machine learning algorithm which repeatedly partitions observations into a fixed number, k, of nonoverlapping clusters (i.e., groups).
B is incorrect. Principal Components Analysis is a long-established statistical method for dimension reduction, not clustering. PCA aims to summarize or reduce highly correlated features of data into a few main, uncorrelated composite variables.
C is incorrect. CART is a supervised machine learning technique that is most commonly applied to binary classification or regression.
老师好，根据题目信息，比较容易排除B选项。然后我就不知道A和C两个选哪一个。A我觉得也对，那我讲讲为什么我觉得C也对吧。
题干说根据一些财务和非财务的特征分成20个小组，其实我们用树的形式也可以分成20个组呀。> <麻烦老师帮忙讲下，谢谢。
