"To obtain information on the corrosion-resistance proper-ties of a certain type of steel conduit, 45 specimens are buried in soil for a 2-year period. The maximum penetra-tion (in mils) for each specimen is then measured, yielding a sample average penetration of x552.7 and a sample standard deviation of s54.8. The conduits were manufac-tured with the specification that true average penetration be at most 50 mils. They will be used unless it can be demon-strated conclusively that the specification has not been met. What would you conclude?"