5555 people are randomly selected and the accuracy of their 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 5555 values have a mean of 101101sec and a standard deviation of 175175sec. Use a 0.020.02 significance level to test the claim that the population of all watches has a mean of 00sec.
a.) The test statistic is
