HSS 2381 Lecture Notes - Lecture 2: Interquartile Range, Multimodal Distribution, Kurtosis

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 2381
• Professor: Victor Emerson

Document Summary

Bimodal (scores must be present between modes, or else they are 2 separate groups) Shorthand way to represent data; describes a typical" value. A measure of the most representative measure of the distribution. Mean: average of scores; sum of deviations around the mean = 0. Median: value above which half the ordered observations fall. There can be more than 1 (ex; bimodal distribution) The measure of spread of scores in distribution; degree to which values in a set of scores are dispersed. Or (largest score smallest score) +1. Vulnerable to extreme scores; volatile and unstable. Inter-quartile range: difference between first and third quartiles. Not affected by extremes; complementary to range. Leaves out top 25% and bottom 25% of scores. O2 = (x - )2 / n. Variance for sample: n-1 gives unbiased estimate of population variance. S2 = (x - m)2 / n - 1. Helps predict next score (cannot be done if std dev is large)