Sample Size Illustrations, Confidence Intervals, & Margins of Error: Jeffreys Method Tables for Attorneys & Experts: 90 Percent Confidence LevelThis volume will assist both non statisticians and statisticians in determining an appropriate sample size to be taken and the confidence intervals and margins of error for samples that have already been taken using the Jeffreys method at the 90 percent confidence level. This volume is designed to help with a specific kind of sample, one in which each member can be assigned into one of two groups (defective or not, good or bad, working or unemployed,