Please help Thank you 5.1 Rickman et al. [1974] made a study of changes in serum
ID: 2921725 • Letter: P
Question
Please help Thank you 5.1 Rickman et al. [1974] made a study of changes in serum cholesterol and triglyceride levels of subjects following the Stillman diet. The diet consists primarily of protein and animal fats, restricting carbohydrate intake. The subjects followed the diet with length of time varying from 3 to 17 days. (Table 5.4). The mean cholesterol level increased significantly from 215 mg per/100 mL. at baseline to 248 mg per/100 mL. at the end of the dict. I n this problem, we deal with the (a) Make a histogram or stem-and-leaf diagram of the changes in triglyceride levels (b) Calculate the average change in triglyceride level. Calculate the standard error of the difference. (c Test the significance of the average change. (d) Construct a 90% confidence interval on the difference. (e) The authors indicate that subjects (5,6), (7,8), (9,10), and (15.16) were "repeaters," that is, subjects who followed the diet for two sequences. Do you think it is 142 ONE- AND TWO SAMPLE INFERENCE Table 5.4 Diet Data for Problem 5.1 Weight (kg) Subject DieInitia FilBaseline Final (g/100 ml) Days on 54.6 49.6 564 528 58.6 55.9 130 59 546 174 60.0 56.7 148 57.3 555 62.7 596 63.6 596 71.4 69.1 72.7 70.5 49.6 47.1 204 78.2 750 182 55.9 532 10 71.8 68.6 718 668 134 70.5 66.8 159 122 17 154 80,74 '58 180 183 10 100 13 108 110 15 16 14 reasonable to include their data the "second time around" with that of the other sub- jects? Supposing not, how would you now analyze the data? Carry out the analysis. Does it change your conclusions?
Explanation / Answer
a)
Stem-and-Leaf Display: Change Stem-and-leaf of Change N = 16
Leaf Unit = 10
1 -0 9
1 -0
1 -0
5 -0 3222
6 -0 1
8 0 00
8 0 223
5 0 55
3 0 7
2 0 8
1 1 0
b) Average change in Triglyceride level and SE of change
Variable N Mean SE Mean
Change 16 15.6 12.9
c) Test for significance of change
One-Sample T
Test of = 0 vs 0
N Mean StDev SE Mean 95% CI T P
16 15.60 12.90 3.23 (8.73, 22.47) 4.84 0.000
Since P-value for the test is less than 0.05 (level of significance) thus it can be concluded that change is significant.
d) One-Sample T
Test of = 0 vs 0
N Mean StDev SE Mean 90% CI T P
16 15.60 12.90 3.23 (9.95, 21.25) 4.84 0.000
The 90 % confidence interval for change is (9.95, 21.25) it indicates that data is against the null hypothesis