This is the official reference book for the Statistical Examination Data Science Expert Exercise. I bought it because there were parts I wanted to know. I am selling it now that I have finished studying the necessary parts. As a reference, I have passed the Statistical Examination Grade 1 and the G-certification and DS-certification exams, and I feel that this book explains the core parts of those exams even more clearly. Also, the content on optimization is explained with concrete examples, and I think the mathematical content is excellent. #StatisticalExamination