A quality engineer inspects a sample of 150 switches from a large shipment of which 8% fail to conform to specifications. (a) Test the hypothesis according to which the true shipment proportion is 10% or more against the alternative that it is smaller than 10%. Use a significance level of 5% (state the null and the alternative hypothesis, the test statistic and the conclusion). (10 points) (b) Compute a 90% confidence interval for the true shipment proportion. Is your finding consistent with your answer in (a) (Explain why or why not)