wristwatches is checked, with positive errors representing watches
that are ahead of the correct time and negative errors representing
watches that are behind the correct time. The 50 values have a mean
of 102sec and a standard deviation of 205 sec. Use a 0.01
significance level to test the claim that the population of all
watches has a mean of 0 sec.
the claim that the mean is equal to 0
claim that the mean is equal to 0