In: Statistics and Probability
An assembly plant orders a large shipment of electronic circuits each month. The supplier claims that the population proportion of defective circuits is ρ=0.04. When a shipment arrives, the plant manager selects a random sample of 300 circuits that are tested and the sample proportion of defective circuits is computed. This result is used for a hypothesis test to determine if there is sufficient evidence to conclude that the population proportion of defectives circuits from this supplier is greater than 0.04. The hypotheses are H0: p < 0.04 and Ha: p> 0.04 .
a) For a level of significance of α=0.025, what value does the sample proportion need to exceed in order for the manager to conclude that p> 0.04 ? Round to three decimal places.
b) In a sample of 300 circuits, the manager found 21 that were defective. Determine the p-value associated with the test statistic for the test described above. Round to four decimal places. Please show and explain work.