At the 0.05 level of significance, is there evidence that the mean bone marrow micro vessel density is higher before the stem cell transplant than after the stem cell transplant?

T Stat = 1.8425 is less than the critical value of 1.943, do not Reject. There is not enough evidence to conclude that the mean bone marrow micro vessel density is higher before the stem cell transplant than after the stem cell transplant. 

Interpret the meaning of the P-value in (a)

P value = 0.0575. The probability of obtaining a mean difference in density that gives rise to a T Test Statistic that deviates from 0 by 1.8425 or more is 5.75% if the mean density is not higher before the stem cell transplant than after the stem cell transplant.

Construct and interpret a 95% confidence interval estimate of the mean difference in bone marrow micro vessel density before and after the stem cell transplant?

.1429 + 2.4469 (123.7005 / SQRT 7)

.55

.1429 – 2.4469 (123.7005 / SQRT 7)

= -28.26

-28.26 < u < 200.55

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

You must assume that the distribution of differences between the mean density of before and after stem cell transplant is approximately normal.