Lecture 7 lecture notes

# Lecture 7 lecture notes - Lecture 7 Outliers and...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

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

Unformatted text preview: Lecture 7. Outliers and influential observations Example . Again we consider the Albuquerque Home Prices. Now we shall evaluate outliers and influential observations. Recall our MLR model: > l<-lm(data\$PRICE~data\$SQFT+data\$AGE+data\$CUST) > summary(l) Call: lm(formula = data\$PRICE ~ data\$SQFT + data\$AGE + data\$CUST) Residuals: Min 1Q Median 3Q Max-56871.580-9368.399 2.080 8506.354 63302.217 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 7248.077 8452.629 0.857 0.39437 data\$SQFT 63.914 4.712 13.565 < 2e-16 *** data\$AGE-428.913 168.111-2.551 0.01313 * data\$CUST 14931.462 5372.717 2.779 0.00715 **--- Signif. codes: 0 *** 0.001 ** 0.01 * 0.05 . 0.1 1 Residual standard error: 17420 on 64 degrees of freedom (49 observations deleted due to missingness) Multiple R-squared: 0.8216, Adjusted R-squared: 0.8132 F-statistic: 98.22 on 3 and 64 DF, p-value: < 2.2e-16 To evaluate outliers and influential observations, we use the generic function influence.measures . > infl<-influence.measures(l) > summary(infl) Potentially influential observations of lm(formula = 100 * data\$PRICE ~ data\$SQFT + data\$AGE + data\$CUST) : dfb.1_ dfb.d\$SQ dfb.d\$AG dfb.d\$CU dffit cov.r cook.d hat 7 0.05-0.08 0.03 0.05-0.09 1.22_* 0.00 0.13 27 0.29-0.33-0.12 0.20-0.37 1.23_* 0.03 0.17 50 0.73-0.67-0.42-0.41-1.22_* 0.52_* 0.31 0.09 89 -0.1389 -0....
View Full Document

## This note was uploaded on 06/21/2009 for the course STAT 331 taught by Professor Yuliagel during the Fall '08 term at Waterloo.

### Page1 / 5

Lecture 7 lecture notes - Lecture 7 Outliers and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online