I need to answer the following questions based on a proc univariate normal plot and need help asap.
Can anyone help?
a. Violation of equal mean assumption using a residual plot
.
b. Violation of equal variance assumption using a residual plot.
c. Violation of normality assumption
Using the normal probability plot,
Using the box plot
Using a stem and leaf plot
conduct a statistical test (Ho, Ha, TS, pvalue and conclusion)
d. Flag potential outliers looking at studentized and jackknife residuals. (State the critical value you used ) What does this mean?
e. Flag any high leverage points. (State the critical value you used) . What does this mean?
f. Look at Cook’s D values and make conclusions. State critical value.
g. Make a conclusion about the PRESS statistic.
Hi:
Usually, folks post the code they've tried, any error messages they get and a sample of the data they need to analyze. You have only posted questions, without any data or program. Saying that the plot is a UNIVARIATE plot is useful, but without anything concrete to go on, it's hard to comment.
a,b,c: Testing the assumptions of linear regression and Does your data violate linear regression assumptions?
d http://www-stat.wharton.upenn.edu/~waterman/Teaching/701f99/Class04/class04.pdf
e http://pages.stern.nyu.edu/~churvich/Undergrad/Handouts2/31-Reg6.pdf
f http://www.ats.ucla.edu/stat/sas/webbooks/reg/chapter2/sasreg2.htm
There are quite a few .EDU resources here. Google is your friend.
cynthia
These are questions about regression diagnostic plots. Submit
ODS GRAPHICS ON;
and run PROC REG. Several of these plots are created automatically.
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