Q2. An important hypothesis in hypertension research is that sodium restriction may lower blood pressure. However, it is difficult to achieve sodium restriction over the long term, and dietary counseling in a group setting is sometimes used to achieve this goal. The data on urinary sodium in HW4 Q2.sav on Canvas were obtained on 8 individuals enrolled in a sodium-restricted group. Data were collected at baseline and after 1 week of dietary counseling. Assume the population of urinary sodium is following a normal distribution.

1. What are appropriate hypotheses to test whether dietary counseling is effective in reducing sodium intake over a 1-week period (as measured by overnight urinary sodium excretion)? Explain why.
2. Carry out the test procedure mentioned in part 1). Use = 0.05, and both rejection region and p-value to make a decision.
3. Provide a 95% CI for the true mean change in overnight sodium excretion over a 1-week period. Interpretthe confidence interval.