You are interested in determining if a low-sodium diet (<100 mmol/day) lowers systolic blood pressure in patients with chronic kidney disease (CKD).Forty patients with stage IV CKD with elevated blood pressure were enrolled. Twenty two (22) were provided with a normal sodium diet for 4-weeks and 22 were given a low-sodium diet for 4-weeks. Blood pressure was measured after 4-weeks on the diets.The data are shown below:

Research Question: Does a low-sodium diet decrease systolic blood pressure in patients with stage IV CKD.

	Normal Sodium Diet Systolic BP (mm Hg)	Low Sodium Diet Systolic BP (mm Hg)
	157	191
	171	136
	164	140
	168	150
	151	141
	178	154
	126	163
	179	164
	156	168
	176	130
	183	157
	149	150
	143	122
	155	142
	165	120
	185	128
	167	139
	158	141
	145	131
	177	150
	145	163
	140	145
n	22	22
Mean	160.82	145.59
SD	15.73	16.83

1. If these data were analyzed by a parametric test, what are the assumptions associated with this analysis?
2. 2. State the null and alternative hypotheses for this experiment?
3. Would a one-tailed or two-tailed test be used for this experiment? Explain your answer.?
4. What are the degree's of freedom for this experimental design if you analyzed these data by a parametric test?
5. Name a parametric and a nonparametric statistical test that could be used to analyze the data from this experiment?