A plot in the article “Thermal Conductivity of Polyethylene:

The Effects of Crystal Size, Density, and Orientation on the Thermal Conductivity” (Polymer Eng. and Science, 1972: 204–208) suggests that the expected value of thermal conductivity y is a linear function of 104  1/x, where x is lamellar thickness.

a. Estimate the parameters of the regression function and the regression function itself.

b. Predict the value of thermal conductivity when lamellar thickness is 500 Å.