Question

Consider the variables y, x1 and x5 from Table B.2 of page 555 in the textbook, regarding Solar Thermal Energy Test Data. Book Linear Regression analysis

1. Construct a normal probability plot of the residuals. does there seem to be any problem with the normality assumption?

2. Construct and interpret a plot of the residuals versus the predicted response.

3. Construct plots of the residuals versus each of the regressor variables. Do these plots imply that regressor is correctly specified?

4. Construct partial regression plots of residuals versus regressors from part c. Discuss the type of information provided by these plots.

5. Compute the studentized residuals and the R−student residuals for this model. What information is conveyed by these scaled residuals?

data

y <- c(271.8, 264,238.8,230.7,251.6,257.9,263.9,266.5,229.1,239.3,258,
257.6,267.3,267,259.6,240.4,227.2,196,278.7,272.3,267.4,254.5,224.7,
181.5,227.5,253.6,263,265.8,263.8)

x1 <- c(783.35, 748.45,684.45,827.8,860.45,875.15,909.45,905.55,756,769.35,793.5,801.65,819.65,808.55,774.95,711.85,694.85,638.1,774.55,757.9,753.35,704.7,
666.8,568.55,653.1,704.05,709.6,726.9,697.15)

x5 <- c(13.2, 14.11,15.68,10.53,11,11.31,11.96,12.58,10.66,10.85,11.41,11.91,12.85,13.58,14.21,15.56,15.83,16.41,13.1,13.63,14.51,15.38,
16.1,16.73,10.58,11.28,11.91,12.65,14.06)

*step by step codes required to compile in R studio, No hand written

Answer 1