Question

Trauma and Metabolic Expenditure: The data set “MetabolicExpenditures”contains metabolic expenditures for eight randomly selected patients admitted to a hospital for reasons other than trauma (NonTrauma) and for seven randomly selected patients admitted for multiple fractures (Trauma). (Data from C.L. Long, et al. “Contribution of Skeletal Muscle Protein in Elevated Rates of Whole Body Protein Catabolism in Trauma Patients,” American Journal of Clinical Nutrition, 34: (1981): 1087—1093.) Before collecting the data, the researchers hypothesize that trauma patients have higher metabolic expenditures than non-trauma patients.

c.trauma..NA.	nontrauma
38.5	20.1
25.8	22.9
22	18.8
23	20.9
37.6	20.9
30	22.7
24.5	21.4
NA	20

1. Formally state the null and alternative hypotheses.

2. Check conditions for constructing a t-test.

3. Regardless of your answer to (c), use Welch’s t-test with Satterthwaite’s approximation for the degrees of freedom to test the null hypothesis. (You do not need to use a hand-calculation. You can use a statistical software package, such as R.)

4. Interpret the result of your test in the context of this study.

Answer 1