3. An airplane manufacturer will only purchase aluminum plates of a given size from a supplier if the supplier can demonstrate that the true average pressure needed to crimp the plates exceeds 2000 psi. They set up a test by randomly selecting n:64 plates from the supplier and measuring the pressure needed to crimp the plates. Let u represent the true mean crimping strength. (a) State the null and alternative hypothesis. (b) They observe a sample mean of 2050 psi and standard deviation of 160. Compute the test statistic. (c) Compute the pvalue for this test. (d) If they conduct this test at o: : 0.05, has the supplier demonstrated at this level of signicance that they meet the specication