正态分布图--直方图的关系

1681214182022012345675101520Frequency02516812141820221681214182022Gotthemeanofeachtwovalues231012345675101520Frequency025xnσ/μXσμXZxxx501xσμXZ5σ0-2NormalDistributionStandardNormalDistributionσμXZ0-112-268%zp95%.97722.0...Z0.000.010.02…0.00.1pInsymmetricaldatasets,wherethemeanandmedianarethesame,youcanusetheempiricalruletoexaminethevariability.-3399.7%Thechebyshevrule切比雪夫•Thechebyshevrulestatesthatforanydataset,regardlessofshape,thepercentageofvaluesthatarefoundwithindistancesofkstandarddeviationsfromthemeanmustbeatleast:（1-1/k2）*100%•Considerk=2,theresultoftheformulais75%,thatstatesthatatleast75%ofthevaluesmustbefoundwithin±2standarddeviationsofthemean.