Question 5 2 pts Researchers have postulated that because of differences in diet, Japanese children have a lower mean blood cholesterol level than U.S. children do. Suppose that the mean level for U.S. children is known to be 170. Furthermore, suppose the researchers obtained a sample of n = 100 Japanese children and obtained a sample mean x = 168 and a sample standard deviation s = 3.5 . Let / represent the true mean blood cholesterol level for Japanese children. Refer to your alternative hypothesis, HA , from question 3. If we assume the level of significance is a = 0.01 , obtain the z-score of the rejection region for this situation. Note: Be wary of the sign! Give an answer to 3 places after the decimal, as given by the t-table