Please mention your sources where you obtained certain constant values ( if you use constants)

A 0.15mm-thick film is required for use in packaging a pharmaceutical product at 30C. The partial pressure of O2 is 21kPa outside the package and is 1kPa inside the package. (a) Calculate the volume flow rate per unit area of oxygen through a linear low-density polyethylene film. (b) Calculate the volume flow rate per unit area of oxygen through a polystyrene film. (c) Compare your answers in (a) and (b). Which is better for this type of application? (d) Which do you think would be preferable under high relative humidity, assuming that water vapor could potentially damage the product