During our teaching at master's level we realized the need of a book for a core paper on testing of hypotheses, which could cover most of the syllabi of undergraduate and postgraduate courses, and competitive examinations, prescribed by different Universities. We felt that the students require a book which is solely dedicated to testing of hypothesis syllabi, emphasizing on concept building, detailing of proofs to main theorems, their real-life applications, and critical and analytical remarks to explain and develop more insight of the subject. The book has been written to serve these academic requirements of the students.