For each of the following pairs of polymers, do the following: (1) State whether it is possible to decide whether one polymer has a higher tensile strength than the other; (2) if this is possible, note which has the higher tensile strength and cite the reason(s) for your choice; and (3) if it is not possible to decide, state why. (a) Linear and isotactic poly(vinyl chloride) with a weight-average molecular weight of 100,000 g/mol; branched and atactic poly(vinyl chloride) having a weight-average molecular weight of 75,000 g/mol (b) Graft acrylonitrilebutadiene copolymer with 10% of possible sites crosslinked; alternating acrylonitrilebutadiene copolymer with 5% of possible sites crosslinked (c) Network polyester; lightly branched polytetrafluoroethylene

ENGR 3341 Probability Theory and Statistics Prof. Gelb Week 2 homework solutions Textbook problems: Section 1.5: Problem 25: A professor thinks students who live on campus are more likely to get As in the probability course. To check this theory, the professor combines the data from the past few years: 1. 600 students have taken the course. 2. 120 students have got As. 3. 200 students lived on campus. 4. 80 students lived off campus and got As. Does this data suggest that “getting an A” and “living on campus” are dependent or independent Solution: let C be the event that a random student lives on campus and A be the event that he/she gets an A. We have: 120