""Two processes are used to produce forgings used in an aircraft wing assembly. Of 200 forgings selected form process1, 10 do not conform to the strength specs, whereas 300 forgings selected from process 2, 20 are nonconforming.
a) Estimate the fraction nonconforming for each process.
b) Test the hypothesis that the two processes have identical fractions nonconforming. Use a = 0.05.
c) Construct a 90% confidence interval on the difference in fraction nonconforming between the two processes.""