The mean ±1 sd of the 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 sdof ln {calcium intake (mg)} among 40 females, 12 to 14 years of age, above the poverty level is 6.80±0.76

Question 8.3 – What is the appropriate procedure to test for a significant difference in means between groups?

Question 8.4 – Implement the procedure in Problem 8.3 using the critical-value method.

Question 8.5 – What is the p-value corresponding to your answer in Problem 8.4?

Question 8.6 – Compute a 95% CI for the difference in means between the two groups?

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Table 8.20 - Overnight sodium excretion (mEq/8hr) before and after dietary consulting.

Person	Week 0 - Baseline	Week 1	Difference
1	7.85	9.59	-1.74
2	12.03	34.50	-22.47
3	21.84	4.55	17.29
4	13.94	20.78	-6.84
5	16.68	11.69	4.99
6	41.78	32.51	9.27
7	14.97	5.46	9.51
8	12.07	12.95	-0.88
  x¯ s	  17.65   10.56	  16.50   11.63	  1.14   12.22

 

Problem 8.58 – What are appropriate hypothesis to test whether dietary counseling is effective in reducing sodium intake over a 1 week period (as measured by overnight urinary sodium excretion)?

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

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

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Table 8.29 – Comparison of Blood Glucose level between men with and without stenosis.

Â	No stenosis (n=356)	Stenosis (n=108)
	Mean sd	Mean sd
Blood glucose (mmol/L)	5.3 1.4	5.1 0.8

Problem 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: F 355,107,.95 =1.307;F355,107,.975 = 1.377).

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

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Table 8.40 Mean HgbA1c 1 year before and 1 year after use of the insulin pump.

ID	Mean HgbA1c 1 year before (%)	Mean HgbA1c 1 year after (%)	Before – After (%)
1	6.7	7.0	-0.3
2	7.4	7.4	0
3	9.2	8.6	0.6
4	9.6	8.1	1.5
5	7.4	6.8	0.6
6	8.1	7.0	1.1
7	10.8	8.5	2.3
8	7.1	7.7	-0.6
9	7.9	9.7	-1.8
10	10.8	7.7	3.1
Mean   sd	8.5   1.5	7.9   0.9	0.65   1.44

 

Problem 8.163 – What test can be used to compare the mean HgbA1c 1 year before vs. mean HgbA1c 1 year after use of the insulin pump?

Problem 8.164 – Perform the test in Problem 8.163, and report a two-tailed p –value.

Problem 8.165 – Provide a 95% CI for the mean difference in HgbA1c before minus the mean HgbA1c after use of the insulin pump.