Question: A manufacturing company receives a shipment of 1,000 bolts of nominal shear strength 4,350 lb. A quality control inspector selects five bolts at random and measures the shear strength of each. The data are:
4,320 4,290 4,360 4,350 4,320
a. Assuming a normal distribution of shear strengths, test the null hypothesis that the mean shear strength of all bolts in the shipment is 4,350 lb versus the alternative that it is less than 4,350 lb, at the 10% level of significance.
b. Estimate the p-value (observed significance) of the test of part (a).
c. Compare the p-value found in part (b) to α = 0.10 and make a decision based on the p-value approach. Explain fully.