pen 12 jan 2011 analysis - 9.6 close, page-9

here we go


last paragraph in "The normal curve and percentiles" (the section with the blue bell shaped normal cuve)

"Percentiles represent the area under the normal curve, increasing from left to right. Each standard deviation represents a fixed percentile. Thus, rounding to two decimal places, −3 is the 0.13th percentile, −2 the 2.28th percentile, −1 the 15.87th percentile, 0 the 50th percentile (the mean and median of the distribution), +1 the 84.13th percentile, +2 the 97.72th percentile, and +3 the 99.87th percentile. Note that the 0th percentile falls at negative infinity and the 100th percentile at plus infinity."