PSYCH 100A Lecture Notes - Lecture 6: Sigma Xi, Squared Deviations From The Mean, Inflection Point
Document Summary
Pick the number that is between 2 bars of the same value: population mean: (equation) u= (sigma xi)/n. Inflection point = where concave switches (where concave meets) Chapter 6: percentiles, percentiles, percentile ranks, & standard scores tell us position of a point within its distribution, percentile = score (ex. How to calculate: pick a certain value in the set of data: 1. ) look at & below the certain value, ex. ) 1,2,3,4,5,6,7,8,9,10 (5 and below = 50th percentile = 1,2,3,5,5,6,7,8,9,10 (5 and below = 50th percentile = 1,2,5,5,5,5,7,8,9,10 (60th percentile bc there are 6 points that are at 5 and below: 2. , percentile rank = percentage %%%% (ex. 81 is 4%: why do we need standard scores, moving from a score of 81 to a score of 90 --> percentile rank jumps from 4% to. 28: but moving from 91 to 100 = percentile rank jumps from 32% to 100% So on the graph, -1 to 0 is 34%.
