For the test of hypothesis in Example 9.1, the average hourly wage x for a random sample of 100 New Brunswick clerical workers might provide a good test statistic for testing Ho: 14 versus H: 14 If the null hypothesis Ho is true, then the sample mean should not be too far from the population mean = 14. Suppose that this sample produces a sample mean = 15 with standard deviation s = 2. Is this sample evidence likely or unlikely to occur, if in fact Ho is true? You can use two measures to find out. Since the sample size is large, the sampling distribution of x is approximately normal with mean = 14 and standard error of Vn, estimated as 

SE= 0.2 n V100 The test statistic x = 15 lies p 15-14 z= = 5 0.2