# hw2 - HW 2 for Stat 7249 Spring 2009 Due February 3 Reading...

This preview shows pages 1–2. Sign up to view the full content.

HW 2 for Stat 7249 - Spring 2009 Due February 3 Reading in text for this assignment Chapters 3-5 Datasets none for this assignment 1. DB Problem 5.1 2. DB Problem 7.1 3. Anscombe residuals are a type of residuals constructed to more closely follow a normal distri- bution than Pearson’s residuals. The idea is to transform Y , using a function A ( Y ) so that A ( Y ) is as close to normal as possible. For likelihoods based on glm’s, the function A ( · ) is given by A ( · ) = Z V 1 / 3 ( μ ) (1) Then, residuals are based on A ( y ) - A ( μ ). The variance of A ( Y ) can be (ﬁrst order) approx- imated as A 0 ( μ ) q ( V ( μ )). Derive the Anscombe residual for the gamma distribution. Using R, take a sample of size 500 from a gamma distribution and examine the distribution of the Pearson and Anscombe residuals. Comment. Do this for several diﬀerent values for t he parameters of the Gamma distribution. 4. Suppose a population of individuals is partitioned into two sub-populations or groups,

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 2

hw2 - HW 2 for Stat 7249 Spring 2009 Due February 3 Reading...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online