The breaking strengths of cables produced by a certain manufacturer have a mean, , of pounds, and a standard deviation of pounds.

The breaking strengths of cables produced by a certain manufacturer have a mean, , of pounds, and a standard deviation of pounds. It is claimed that an improvement in the manufacturing process has increased the mean breaking strength. To evaluate this claim, newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be pounds. Can we support, at the level of significance, the claim that the mean breaking strength has increased? (Assume that the standard deviation has not changed.)