(a) What is meant by data normalization in machine learning? (Remember that in this course "normalization" is understood in the wide sense and includes the transformations perfomed by Normalizer, Standard Scaler, etc., in scikit-learn.)[2 marks] (b) Briefly describe the class Standard Scaler in scikit-learn, paying particular attention to its fit and transform methods.[5 marks] (c) Compare and contrast the classes StandardScaler and RobustScaler inscikit-learn.[3 marks] (d) Briefly describe the class MinMaxScaler in scikit-learn. (e) Consider the following training set:

What is its normalized version, in the sense of MinMaxScaler? Apply the same transformation to the test set

(f) What is meant by data snooping in machine learning? Explain, briefly and in plain English, what the following code is doing (assuming that all functions that it uses have been loaded from the relevant libraries).