Let X1 and X2 have independent gamma distributions with parameters , and , , respectively. Let W = X1/(X1 + X2). Use a method similar to that given in the derivation of the F distribution (Example 5.2-4) to show that the pdf of W is g(w) = ( + ) ()() w1(1 w) 1, 0 < w < 1.We say that W has a beta distribution with parameters and . (See Example 5.2-3.)

Unit 4 Notes: Ethics of Experiments with Humans and Animals Week 3: 24 Jan 2018 Key Terms Key Terms 1. Voluntary response: a type of sampling that is not random and just uses a general call-out to get volunteers to participate 2. Informed consent: should be used in EVERY type of sample. The researcher can choose the sample, but the people chosen...