Brief Solution for Problem for Statistical Methods for Bioscience II | HORT 572, Exams of Data Analysis & Statistical Methods

Download Brief Solution for Problem for Statistical Methods for Bioscience II | HORT 572 and more Exams Data Analysis & Statistical Methods in PDF only on Docsity! Stat/For/Hort 572 – Midterm II, Spring 2004 — Brief Solutions for Problem 2 The experiment is a randomized complete block design. The plots are the experimental units and the fields are the blocks. Arrange the data in the file n.dat. trt blk yield site field 1 1 10.75 1 1 1 2 12.37 1 2 1 3 6.33 2 3 1 4 11.19 2 4 2 1 18.66 1 1 2 2 16.36 1 2 2 3 14.97 2 3 2 4 15.48 2 4 3 1 21.15 1 1 3 2 19.39 1 2 3 3 19.02 2 3 3 4 16.78 2 4 4 1 20.76 1 1 4 2 17.57 1 2 4 3 20.25 2 3 4 4 17.91 2 4 5 1 13.97 1 1 5 2 15.89 1 2 5 3 11.64 2 3 5 4 11.19 2 4 6 1 19.84 1 1 6 2 19.56 1 2 6 3 14.15 2 3 6 4 10.02 2 4 7 1 17.24 1 1 7 2 15.89 1 2 7 3 11.69 2 3 7 4 9.06 2 4 We analyze the data using the following SAS commands. data nitro; infile "n.dat" missover firstobs=2; input trt blk yield site field; run; proc glm data=nitro; classes trt blk; model yield = trt blk; output out=nitro2 p=pred r=resid; means trt / lsd lines; contrast "control vs trt" trt 6 -1 -1 -1 -1 -1 -1; contrast "FP linear" trt -3 -1 1 3 0 0 0; contrast "FP quadratic" trt 1 -1 -1 1 0 0 0; contrast "FP cubic" trt -1 3 -3 1 0 0 0; run; proc plot data=nitro2; plot resid*pred / vref=0; run; The (edited) SAS output looks like the following. The residual plot (not shown) looks fine when checking for the usual 4 assumptions. A mean profile plot shows that there might be an interaction between the treatments and blocks, but a formal test would be required to test for the interaction. Dependent Variable: yield Sum of Source DF Squares Mean Square F Value Pr > F Model 9 352.1452571 39.1272508 9.18 <.0001 Error 18 76.7378286 4.2632127 Corrected Total 27 428.8830857 Source DF Type I SS Mean Square F Value Pr > F trt 6 258.8758857 43.1459810 10.12 <.0001 blk 3 93.2693714 31.0897905 7.29 0.0021 Source DF Type III SS Mean Square F Value Pr > F trt 6 258.8758857 43.1459810 10.12 <.0001 blk 3 93.2693714 31.0897905 7.29 0.0021 t Tests (LSD) for yield Alpha 0.05 1