A professor gives his class a final examination that, he knows from years of experience, yields a population mean of 88. His present class of 22 obtains a mean of 92 and a standard deviation of 4. Is he correct in assuming that the performance of the most recent class is significantly better than that of other classes? He set his significance level at ? = .05 Null Hypothesis Alternative Hypothesis Critical Region Test statistic A. The current class mean is equal to the population mean. B. The current class mean is less than or equal to the population mean. C. The current class mean is not equal to the population mean. D. The current class mean is greater than the population mean. E. 1.721 F. ±2.080 G. 4.7 H. 2.2.