This book is part of a series of textbooks written specifically for the OCR modular mathematics syllabus. Each book or half-book corresponds exactly to one module. Both teachers and students will enjoy using these books. Each chapter starts with a short list of learning objectives, and mathematical ideas are explained carefully and clearly, with many stimulating worked examples. There are plenty of exercises throughout, along with revision exercises and mock exam papers – all written by experienced examiners. Statistics 2 introduces the normal distribution and the Poisson distribution. It also covers sampling and hypothesis testing.