For the following research scenarios, indicate the research, alternative and null hypotheses, test the null with the appropriate test (CI with z or t distribution, z- or t-test), and state conclusions. A nurse researcher is interested in whether Black Americans who have a social support system of four or more people differ in blood pressure compared to the average systolic blood pressure of 120, sd = 10. Her group of 100 Black Americans averaged 119 on systolic blood pressure.