Increased blood vessel formulation is a predictive factor in survival for a certain disease. One treatment is stem cell transplantation with thepatient's own stem cells. The accompanying data table represents the microvessel density for patients who had a complete response to the stem cell transplant. The measurements were taken immediately prior to the stem cell transplant and at the time the complete response was determined.

• At the 0.01 level ofsignificance, is there evidence that the mean microvessel density is higher before the stem cell transplant than after the stem celltransplant?

(a) What is the ^tstat?

(b)What is the p-value?

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

(c.2) Construct a 90% confidence interval.