APMA 3120 Chapter Notes - Chapter 1-2: Statistical Significance, Quartile, Interquartile Range
18 Feb 2016
School
Department
Course
Professor
Document Summary
Statistic success stories and cautionary tales: statistics: collection of procedures/principles for gathering data & analyzing information to help make decisions when faced with uncertainty. In general we prefer the mean as a measure of center because it includes information from all the observations. However, if a distribution has skewness, the median is better because it is less afected by those few extreme values. Resistant measure of center: q1 is lower quartile and has of the data below it and q3 has below, five number summary gives good description of quantitative data set- min, q1, median, d. Interquartile range, iqr = q3 q1 gives the range of the middle half of the data. Any value below q1 1. 5 iqr will be considered a low outlier, and any value above q3 + 1. 5. Iqr will be considered a high outlier: standard deviation (s): measure of spread for mean, tells how far observations tend to be from their mean s.
