Drawing upon over 40 years of experience, the authors of this highly accessible book provide business professionals with a clear and methodical approach to essential statistical procedures. The ninth edition clearly explains the basic concepts and procedures of descriptive and inferential statistical analysis. It features a new emphasis on expressions involving sums of squares and degrees of freedom as well as a stronger stress on the importance of variability. This accessible approach will help business professionals tackle such perennially mystifying topics as the standard deviation, variance interpretation of the correlation coefficient, hypothesis tests, degrees of freedom, p-values, and estimates of effect size.