# Statistics Ch 3

 The flashcards below were created by user Timmit on FreezingBlue Flashcards. Median If n is an even number (Formula) (n/2 + (n/2)+1)/2 Median If n is an odd number (Formula) (n+1)/2 If the data are skewed, the ___________ is a good measure of central tendency. Median Population Variance (Formula) Sample Variance Empirical Rule Values 68% 95% 99.7% Population Mean (Formula) Where xi is the midpoint, xifiis the frequency of the ith class, n is the number of classes. Population z-score (Formula) z= x-u/sigma Sample z-score (formula) z=x-xbar/s Determining the kth percentile, Pk Where k is the percentile of the data value and n is the number of individuals in the data setIf i is an integer, the kth percentile is the ith data value.      If i is not an integer, find the mean of the observations on either side of i. Lower (first) quartile,  Q1 (k=25) Upper (third) quartile, Q3 (k=75) Inter-quartile range: IQR (formula) Q3-Q1 Lower inner fence Formula Q1 -(1.5 × IQR) upper inner fence Formula Q3 +(1.5 × IQR) AuthorTimmit ID258778 Card SetStatistics Ch 3 DescriptionStatistics Updated2014-01-28T04:48:37Z Show Answers