Give an example of a person in reality who holds both a leadership role and a management role. Indicate at least 4 roles in leadership that this person has performed, and at least 4 different jobs in this person's management role. Explain clearly the role of the above character in each of the above jobs

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1. which statement is true if we are testing the null hypothesis at the 95% confidence level? a. the difference of the two means is significant, so the null hypothesis must be rejected. b. the difference of the two means is significant, so the null hypothesis must be accepted. c. the difference of the two means is not significant, so the null hypothesis must be rejected. d. the difference of the two means is not significant, so the null hypothesis must be accepted.