The article “Influence of Freezing Temperature on Hydraulic Conductivity of Silty Clay” (J. Konrad and M. Samson, Journal of Geotechnical and Geoenvironmental Engineering, 2000:180-187) describes a study of factors affecting hydraulic conductivity of soils. The measurements of hydraulic conductivity in units of 10-8 cm/s (y), initial void ratio (x1), and thawed void ratio (x2) for 12 specimens of silty clay are presented in the following table.

a. Fit the model y = β0 + β1x1 + ε . For each coefficient, test the null hypothesis that it is equal to 0.

b. Fit the model y = β0 + β1x2 + ε . For each coefficient, test the null hypothesis that it is equal to 0.

c. Fit the model y = β0 + β1x1 + β1x2 + ε . For each coefficient, test the null hypothesis that it is equal to 0.

d. Which of the models in parts (a) to (c) is the best of the three? Why do you think so?

The Ring Gyges.docx 1) What, exactly, is Glaucon's argument That is, what message does he want us to accept, and what material does he provide to support his message ● Everyone hates having injustice done to them, and laws are only put into place to avoid that mistreatment ● In the absence of laws men would act unjustly ● He uses the story about the Ring of Gyges to support his claim. Gyges used his newfound power to get and do whatever he wanted. Glaucon believes that any other person in Gyges shoes would have behaved the same way. 2) Do you agree with Glauco