Question

Multiple myeloma, or blood plasma cancer, is characterized by increased blood vessel formulation (angiogenesis) in the bone marrow that is a predictive factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with the patient's own stem cells. The data show below represents the bone marrow microvessel density for patients who has a complete response to the stem cell transplant (as measured by blood and urine tests). The measurements were taken immediately prior to the stem cell transplant and at the time the complete response was determined.

Patient             Before               After
     1                      158                   284
     2                     186                   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 evidence that the mean bone marrow microvessel density is higher before the stem cell transplant than after the stem cell transplant? (Be sure to include the null and alternate hypotheses as well as the value of the test statistic. State the decision rule used and write you conclusion in a complete sentence.)

(b) Interpret the meaning of the p-value in (a).

(c) Construct and interpret a 95% confidence interval estimate of the mean difference in bone marrow microvessel density before and after the stem cell transplant.

(d) What assumption is necessary about the population distribution in order to perform the test in (a)?

Answer 1