Biological Data Analysis: Homework 8

Due Tuesday, Oct. 27

You must type this and all other homework assignments. Do not e-mail the assignment to me; turn it in early (at 322 Wolf) for a foreseeable absence, or turn it in late after an unexpected absence from class.

1. Do Welch's anova and a Kruskal-Wallis test on the data set you've been using for the recent homework assignments. You may use either my spreadsheets, or SAS; you do not need to use both a spreadsheet and SAS. Report the P value for the one-way anova you did last time, the Welch's anova, and the Kruskal-Wallis test.

2. Two technicians, "Brad" and "Janet" (these are real data, but I've changed their names), have measured the uptake of a fluorescently labelled protein in rat kidneys. They want to know whether their techniques for anesthetizing the rats, cutting them open, and injecting the fluorescently labelled protein are the same. They also want to know whether it's worthwhile to use multiple rats, and whether it's worthwhile to make multiple measurements from each rat. Brad operates on three rats, then after 60 minutes, measures the protein in 10 samples from each rat. Janet does the same on three rats of her own. The data are below question 3. Analyze the data using a nested anova. Report the F-statistics and P-values for each null hypothesis. You must use my spreadsheet, and you must also analyze the data using SAS. If you get the same P-values in SAS as you did with the spreadsheet (note that SAS may round to a smaller number of decimals), you only need to print the SAS output (from the .lst file). If you get a different result from my spreadsheet and from SAS, you must also print the .log file and your SAS program (your .sas file), so I can try to figure out what you did wrong.

3. Interpret the results of question 2--what would you recommend to Brad and Janet?


Tech  Rat  Protein

Janet   1   1.119
Janet   1   1.2996
Janet   1   1.5407
Janet   1   1.5084
Janet   1   1.6181
Janet   1   1.5962
Janet   1   1.2617
Janet   1   1.2288
Janet   1   1.3471
Janet   1   1.0206
Janet   2   1.045
Janet   2   1.1418
Janet   2   1.2569
Janet   2   0.6191
Janet   2   1.4823
Janet   2   0.8991
Janet   2   0.8365
Janet   2   1.2898
Janet   2   1.1821
Janet   2   0.9177
Janet   3   0.9873
Janet   3   0.9873
Janet   3   0.8714
Janet   3   0.9452
Janet   3   1.1186
Janet   3   1.2909
Janet   3   1.1502
Janet   3   1.1635
Janet   3   1.151
Janet   3   0.9367
Brad    5   1.3883
Brad    5   1.104
Brad    5   1.1581
Brad    5   1.319
Brad    5   1.1803
Brad    5   0.8738
Brad    5   1.387
Brad    5   1.301
Brad    5   1.3925
Brad    5   1.0832
Brad    6   1.3952
Brad    6   0.9714
Brad    6   1.3972
Brad    6   1.5369
Brad    6   1.3727
Brad    6   1.2909
Brad    6   1.1874
Brad    6   1.1374
Brad    6   1.0647
Brad    6   0.9486
Brad    7   1.2574
Brad    7   1.0295
Brad    7   1.1941
Brad    7   1.0759
Brad    7   1.3249
Brad    7   0.9494
Brad    7   1.1041
Brad    7   1.1575
Brad    7   1.294
Brad    7   1.4543


Return to the Biological Data Analysis syllabus

Return to John McDonald's home page

This page was last revised October 23, 2015. Its URL is http://udel.edu/~mcdonald/stathw8.html