# Residual plot

• Jun 27th 2009, 04:22 AM
luysion
Residual plot
hey guys, just working on residuals. first post and hopefully not the last :P
so here the question much appriciation to however so helps :)
note- im finding it extremely hard to intrepret which is of random scatter and which is of a pattern.

which of the following residual plots shows that a linear model (the model used in the first place) is inappropriate to use to display the correlation between the two variables.

or

by the way hello http://mathguru.freeforums.org/image...on_e_smile.gif gd forums
• Jun 27th 2009, 03:31 PM
pickslides
The second residual plot has too many positive values to justitfy the regression suggested.

For the regression model to be stable the sum of residuals $\displaystyle \rightarrow 0$
• Jun 27th 2009, 04:37 PM
luysion
hey thanks pickslides,

just wondering though, in A can we state that there is no observable trend with the residuals? because it sort of seems like its got a decreasing trend, however the trend being extremely vague
• Jun 28th 2009, 02:40 AM
pickslides
You cannot determine an increasing or decreasing trend from a residual plot.

You are correct in saying the correlation is weak given the magnitude of each residual.