This book has been written with the intent to acquaint the students with the basic facts of Inference and Decision Theory. It is suitable for both undergraduate and first semester graduate (Masters) students, who actually engage in Inference and Decision Theory, in the fields of Mathematical Statistics, Engineering, Physical and Natural Sciences, Social and Environmental Sciences. The overwhelming majority of students and practitioners in the aforementioned Sciences still lack the necessary backgrounds to take full advantage of the rapidly accumulating technical literature in Mathematical Statistics and Decision Theory. With these basic facts in mind, this text has been written so as to avoid Mathematical derivations insofar as possible. However, certain basic and fundamental ideas underlying the principles of Statistical Inference and Linear Mathematics (Algebra) must be thoroughly understood if one is to obtain an appreciable knowledge of the contents of this book and in learning to apply them to their own fields of interest.