Resistant example sample of ve numbers 1 5 3 5 7 what

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: y are not resistant! Resistant Example Sample of "ve numbers: 1, 5, 3, 5, 7 ' What is the mean? 4.2 ' What is the median? 5 1, 5, 3, 5, 700 ' What is the mean? 142.8 ' What is the median? 5 Strategy for dealing with Outliers Investigate outliers for accuracy and appropriateness Carry out the statistical procedures with and without the outliers If the conclusions are the same for both analyses, leave them in If the conclusions are di#erent, consideration should be given to a transformation of the data or to alternative procedures that are more resistant (Chapter 4) Sometimes "nding outliers is the goal of our analysis! Data Transformations Logarithm (log) transformations Use if the ratio of the largest to the smallest observation is greater than 10 Use for positively skewed data for two or more groups when the group with larger average also has the larger spread (We did this for the rainfall data) More Transformations Square root: if data are counts Reciprocal: if data are waiting times or time to failure Logit = log(p/(1-p)): if data are proportions or percents Authors prefer graph...
View Full Document

This note was uploaded on 10/03/2011 for the course STAT 511 taught by Professor Eggett,d during the Winter '08 term at BYU.

Ask a homework question - tutors are online