This text has been updated and transformed using new material for use with computer technology. It retains its appeal, written in non-mathematical, "user-friendly" English for anyone who finds figures mystifying - only concepts or symbols essential to an understanding of the subject are introduced. The topics are progressively staged in a statistical building block technique. This text is both flexible and practical and can be used entirely with or without computers - for the former there are computer-linked examples with easy introductions to most common computer packages. The text should be useful for non-mathematicians and should appeal to those who want to understand figures and their presentation, and to acquire a quantitative background whether the student is at college, university or on a distance/open learning course.