The fourth day of Online Bootcamp on “Machine Learning and Artificial Intelligencestarted at 10:00 AM.The Guest speaker of the day was Mr.PrashantGangwar Sr. Consultant Tec stack New Delhi. In continuation with the concept of Machine Learning, speaker asked to submit the assessment test given on Day-3. Further he shared the study material for Day-4. Mr. Prashant started his session with briefing about the previous day topics and also asked queries on the topics he has covered on Day-1, Day-2&Day-3. Mr. Prashant started with overview of Regression. The speaker explained types of regression its formulae and its implementation using python.He told about confusion matrix, error calculation, decision tree etc. With above concepts, speaker also discussed classification. He told students where we can use random forest regressor and where we can use random forest classifier also briefed about the important questions for interview such as Boot strap aggregation, multiple regression formulae and many more. At last, the problem-solving session was taken where the speaker solved the queries of students and debugged the problems they are facing. He gave assignment to all students based on topics covered in Day-4. The day ended with introduction to clustering and sharing of Iris data set to perform different operations.