[R] Predict

[Ricardo L Gómez]

Dear Cristopher,

I have a question and hope you may help me...I designed a model with a 
data set, the model

Call:
lm(formula = outcom ~ vari1 + vari2 + dummy1 + dummy2)

Residuals:
Min 1Q Median 3Q Max
-0.7090 -0.2648 0.1466 0.2167 0.7513

Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 1.528295 0.205280 7.445 4.79e-07 ***
vari1 0.067471 0.042248 1.597 0.12676
vari2 0.009433 0.040919 0.231 0.82015
dummy1 1.275861 0.256066 4.983 8.27e-05 ***
dummy2 1.326405 0.414477 3.200 0.00471 **
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 0.458 on 19 degrees of freedom
Multiple R-squared: 0.9772, Adjusted R-squared: 0.9724
F-statistic: 203.8 on 4 and 19 DF, p-value: 2.564e-15

but now, using this model, I need to calculate the predicted value of 
OUTCOM (only for one observation) , when vari1=8 and vari 2 =64, and 
also the confidence interval....(the data set has total of 24 
observations),

-- 
Ricardo Gómez 
Center for International Education
University of Massachusetts-Amherst, School of Education
http://www.umass.edu/cie/

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