1. Suppose 2% of cotton fabric rolls and 4% of nylon rolls contain flaws. Of the rolls used by a manufacturer, 70% are cotton and 30% are nylon. What is the probability that a randomly selected roll used by the manufacturer contains flaws? Round your answer to three decimal places (e.g. 98.765).
2. Heart failures are due to either natural occurrences (83%) or outside factors (17%). Outside factors are related to induced substances (73%) or foreign objects (27%). Natural occurrences are caused by arterial blockage (56%), disease (27%), and infection (e.g., staph infection) (17%). Round your answers to four decimal places (e.g. 98.7654).
a) Determine the probability that a failure is due to induced substance.
b) Determine the probability that a failure is due to disease or infection.