hw5ans - Statistics 500 Fall 2009 Solutions to Homework 5...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Statistics 500 – Fall 2009 Solutions to Homework 5 1 1. Diagnostics for the diet and longevity study (a) Independence: look at the study design. Treatments were randomly assigned to individual mice; longevity was measured on individual mice. So, e.u. = mouse is the same as the o.u. = mouse. No obvious problem with lack of independence. (b) Equal variances: a variety of diagnostic methods (e.g. residual vs predicted value plot, box plots of the observations in each group, or calculation of the within group s.d.) or tests (Levene’s test) are acceptable. All groups have similar variabilities. No problem with equal variances. (c) Normality: If you pool the residuals, then plot a histogram or quantile-quantile plot, you see some deviations from normality: there are some especially small values. If you look at each group separately, you see some groups that seem normal and others that do not. I think there is a problem with normality. Other well justified answers were accepted. 30 35 40 45 -25 -15 -5 0 5 10 Predicted Residual -3 -2 -1 0 1 2 3 Theoretical Quantiles S am ple Q uantiles 2) Marker effects in a genome-wide study (a) 10 Markers: numbered 1-10 Here are my computations: marker pvalue adjP 7 0.000 0.004 9 0.000 0.013 1 0.001 0.046 5 0.002 0.046 3 0.002 0.040 6 0.003 0.053 2 0.004 0.050 8 0.004 0.051 4 0.005 0.052 10 0.005 0.047
Background image of page 1

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

View Full DocumentRight Arrow Icon
Statistics 500 – Fall 2009 Solutions to Homework 5 2 63 0.008 0.071 73 0.009 0.072 24 0.010 0.073 17 0.017 0.119
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/11/2012 for the course STAT 500 taught by Professor Staff during the Fall '08 term at Iowa State.

Page1 / 4

hw5ans - Statistics 500 Fall 2009 Solutions to Homework 5...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online