10.24

Multiple myeloma, or blood plasma cancer, is

characterized by increased blood vessel formulation (angio-

genesis) 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 following data (stored in myeloma ) repre-

sent the bone marrow microvessel density for patients who

had 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 1 2 3 4 5 6 7

Before 158 189 202 353 416 426 441

After 284 214 101 227 290 176 290

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?

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

c. Construct and interpret a 95% confidence interval esti-

mate of the mean difference in bone marrow microvessel

density before and after the stem cell transplant.

d. What assumption is necessary about the population dis-

tribution in order to perform the test in (a)?