PSYC 202 Chapter Notes - Chapter 4: Statistical Parameter, Square Root, Variance

• School: Queen's University
• Department: Psychology
• Course: PSYC 202
• Professor: Ronald R Holden

Document Summary

Population standard deviation = = 2= square root ss n. Draw vertical line down from mean and label it =___. Next, draw the standard deviation line a horizontal line extending from the mean line to about half way to the most extreme score. Add an arrow to the line, going left or right. Samples consistently tend to be more variable than their populations (cid:0) this means samples give a biased estimate of population variability. The first step of finding standard deviation in a sample is the same as in population. However, since we"re dealing with a sample, notation changes from n to n and to m: ss= (x-m)2 definitional formula, ss= x2 - ( x) Complete sample variance equation: s2 = (x-m) Sample standard deviation (s) is the square root of the variance. n-1. S = s 2 = ss n-1 .