Lightbulbs of a certain type are advertised as having an average lifetime of 750 hours. The price of these bulbs is very favorable, so a potential customer has decided to go ahead with a purchase arrangement unless it can be conclusively demonstrated that the true lifetime is smaller than what is advertised. A random sample of 60 bulbs was selected. In this sample, the mean lifetime was 741.8 and the standard deviation was 19.2. What conclusion would be appropriate for a significance level of 0.01?