Textbook in PDF format Essential Statistics: Understanding and Using Data provides students with the tools they need to understand what statistics are, how they work, why they are so important, and how they function in the world. With a focus on step-by-step instruction, Essential Statistics begins each section with a sharp focus on simplified main concepts, followed by expansions into how variation impacts each concept. Readers find this easy-to-read textbook welcoming because of its friendly, patient voice and style and its reliance on real-world examples of where statistics fit in everyday life