A hot-tub manufacturer advertises that with its heating equipment, a temperature of 100°F can be achieved in at most 15 min. A random sample of 42 tubs is selected, and the time necessary to achieve a 100°F temperature is determined for each tub. The sample average time and sample standard deviation are 16.5 min and 2.2 min, respectively.

Does this data cast doubt on the company’s claim? Compute the P-value and use it to reach a conclusion at level .05.