A manufacturer of loose-fill cellulose insulating material provides a table showing the...

A manufacturer of loose-fill cellulose insulating material provides a table showing the relationship between the thickness of the material and its R-value. The manufacturer’s data is shown in the accompanying table.

Calculate the thermal conductivity of the insulating material. Also, determine how thick the insulation should be to provide R-values of

a. R-30

b. R-20