The following data were obtained two months apart for the relationship between refractive index and composition of mixtures of benzene and 1-propanol. Different lots of materials were used in each...

The following data were obtained two months apart for the relationship between refractive index and composition of mixtures of benzene and 1-propanol. Different lots of materials were used in each case.

(a) Determine the relationship between these variables.

(b) Test each term at the x = 0.01 level.