Assignment 1 STP 598, Spring 2007, S. Lohr
Due on Tuesday, January 30, 2007
1. Read Sections 1.1, 1.2, 1.3, and 1.5 of Jiang’s book.
2. Download the statistical package R to your computer from www.r-project.org
3. Read Chapters 1 through 5 of “An Introduction to R” (the pdf file is in the
Help menu of your downloaded copy). The “R reference manual,” also in the
Help menu, tells how to use all the R functions and is a useful resource.
4. For each of the following experiments, construct a Hasse diagram. Then express
it as a mixed model of the form Y=Xβ+Zα+ε. Give the matrices X,β,
Z,α,G,R, and Vexplicitly.
(a) A study of wrinkle creams used 8 women. Four of the women are randomly
assigned to take a daily supplement of green tea extract; the other four
take a placebo pill. Each woman is given bottles of two face creams: Revert
and Regress. For each woman, a coin is flipped. If it is heads, she uses
Revert on the left side of her face and Regress on the right; if tails, she uses
Revert on the right side of her face and Regress on the left. The response
is change in skin elasticity over the experiment.
(b) Use the miles per gallon experiment in exercise 25.15 (page 1080) of the
white book (exercise 24.15, page 1005 of the blue book). To reduce the
dimensions of the matrices, you may assume that there are 3 cars instead
of 5.
5. Do exercise 1.3 in Jiang’s book.
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