Assuming that the distribution of IGF-1 is approximately normal, what test can be used to compare the

Question:

Assuming that the of IGF-1 is approximately normal, what test can be used to compare the mean IGF-1 obtained from the two sources?

Hematology

Insulin-like growth factor 1 (IGF-1) is a hormone that plays an important role in childhood growth and may be associated with several types of cancer. In some studies, it is measured in serum, and in other studies it is measured in plasma. Blood plasma is prepared by spinning a tube of fresh blood containing an anti-coagulant in a centrifuge until the blood cells fall to the bottom. The blood plasma is then poured or drawn off. Blood serum is blood plasma without clotting factors (i.e., whole blood minus both the cells and the clotting factors).

In a multi-center study, IGF-1 was measured in some centers with serum and in other centers with plasma. The following results were obtained:

Table 8.33 Comparison of IGF-11evels measured in serum vs. plasma

IGF-1 (ng/mL) sd mean 140 149.1 42.3 serum plasma 404 49.0 136.6

Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...