STAT 100 Lecture Notes - Lecture 3: Interquartile Range
5 Apr 2016
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Document Summary
: numeric values that represent the average or typical value of a quanitaive. Variaion or measures of dispersion: numeric values that represent the degree to which the values are spread out. Mean=average of a data set (add all data and divide by number of pieces of data) Median=resistant measure of data"s center: must be in ascending order, at least half of ordered values are greater or equal to median, if n is odd, the median is the middle number. If it"s even, it"s the average of the two middle numbers: l(m) = (n+1)/2 (n is the sample size) [ x1 = 2, x2 = 4, x3 = 6 ] l(m) = (3+1)/2 =2: median: m = 4. 0. Variability: if all values are the same, then they all equal the mean. There is no variability: variability exists when some values are diferent from (above or below) the mean. A measure of center alone can be misleading.
