Multiple myeloma, or blood plasma cancer, is distinguished by raised blood vessel formulation (angiogenesis) in the bone marrow that is the predictive factor in survival. One treatment approach empoyed for multiple myeloma is stem cell transplantation with patient's own stem cells. The following data (stored in Myeloma represent bone marrow microvessel compactness for patients who had a complete response to stem cell transplant (as measured through blood and urine tests). The measurements were taken without delay prior to the stem cell transplant and at the time the whole response was determined.
Patient Before After
1 158 284
2 189 214
3 202 101
4 353 227
5 416 290
6 426 176
7 441 290
a. At the 0.05 level of significance, is there confirmation that the mean bone marrow microvessel density is higher before stem cell transplant than after stem cell transplant?
d. What supposition is necessary regarding the population distribution in order to carry out the test in (a)?