Continuous tubing is produced in a plastic extrusion operation through a die orifice whose outside diameter = 2.0 in and inside diameter = 1.5 in. the extruder barrel diameter = 5.0 in and length = 12 ft. the screw rotates at 50 rev/min; it has a channel depth = 0.30 in and flight angle = 16°. the head pressure has a value of 350 lb/in2 and the viscosity of the polymer melt is 90 x 10-4 lb-sec/in2. under these conditions, what is the production rate in length of tube/min, given that the die swell ratio is 1.25.