Hypothesis Testing and Biostatistics

Part 1

7.109 Suppose we wish to test the hypothesis H0: μ = 2 vs. H1: μ ≠ 2. We find a two-sided p-value of .03 and a 95% CI for μ of (1.5, 4.0). Are these two results possibly compatible? Why or why not?

Nutrition
The mean ±1 sd of ln [calcium intake (mg)] among 25 females, 12 to 14 years of age, below the poverty level is 6.56 ± 0.64. Similarly, the mean ± 1 sd of ln [calcium intake (mg)] among 40 females, 12 to 14 years of age, above the poverty level is 6.80 ± 0.76.

8.3 What is the appropriate procedure to test for a significant difference in means between the two groups? 8.4 Implement the procedure in Problem 8.3 using the critical-value method.

8.3. AND 8.4 DOES NOT HAVE TO BE ANSWER BUT I THOUGT YOU NEED TO SEE IT TO ANSWER 8.5 AND 8,6
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8.5 What is the p-value corresponding to your answer to Problem 8.4?

8.6 Compute a 95% CI for the difference in means between the two groups.
Nutrition
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 Table 8.20 were obtained on 8 individuals enrolled in a sodium-restricted group. Data were collected at baseline
and after 1 week of dietary counseling
Table 8.20 Overnight sodium excretion (mEq/8hr) before and after dietary counseling
SEE ATTACHED

8.58 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)?

8.59 Conduct the test mentioned in Problem 8.58, and report a p-value.

8.60 Provide a 95% CI for the true mean change in overnight sodium excretion over a 1-week period.

Cardiology
A study was performed concerning risk factors for carotidartery stenosis (arterial narrowing) among 464 men born in 1914 and residing in the city of Malmö, Sweden [16]. The data reported for blood-glucose level are shown in Table 8.29.

Table 8.29 Comparison of blood-glucose level between men with and without stenosis
SEE ATTACHED

8.111 What test can be performed to assess whether there is a significant difference in mean blood-glucose level between men with and without stenosis? (Hint: F355,107,.95 =
1.307; F355,107,.975 = 1.377.)

8.112 Implement the test mentioned in Problem 8.111, and report a p-value (two-tailed).