Homework 5 Solutions

Assigned: 29 September 2004
Due: 06 October 2004

C:\Documents and Settings\John Bailer\My Documents\baileraj\Classes\Fall 2004\sta402\hw\Homework-5.doc

1. Refer to the 4 group (packaging method)- log-bacterial growth study. In this exercise, you will use SAS/GRAPH to construct figures displaying the means and standard deviations.

a. Construct a figure containing side-by-side boxplots using the INTERPOL=BOX option associated with a SYMBOL statement used with PROC GPLOT.

ODS RTF file='D:\baileraj\Classes\Fall 2003\sta402\hw\hw5-prob1a.rtf’;

proc gplot data=class.meat; title h=1.5 ‘Plot of log(Bacterial count) vs. packaging condition'; title2 h=1 '[boxplot is plotted for each condition]'; symbol1 interpol=box /* plots +/- 2 SD from the mean at each conc */ value=dot;

plot logcount*condition;

run;
ODS RTF CLOSE;

[pic]
b. Construct a figure with the data points plotted. Superimpose the mean plus/minus 2 std. deviation segments on this plot.
ODS RTF file='D:\baileraj\Classes\Fall 2003\sta402\hw\hw5-prob1b.rtf’;

proc gplot data=class.meat; title h=1.5 ‘Plot of log(Bacterial count) vs. packaging condition'; title2 h=1 '[mean +/- 2SD is plotted for each condition]'; symbol1 interpol=STD2T /* plots +/- 2 SD from the mean at each conc */ /* T= add top and bottom to each 2 SD diff */ value=dot;

plot logcount*condition;

run;
ODS RTF CLOSE;

[pic]
c. Construct a horizontal bar chart with the end of the bar at the value of the mean with a 1 SD whisker extending from this bar.
/* from http://www.units.muohio.edu/doc/sassystem/sasonlinedocv8/sasdoc/sashtml/gref/zart-bar.htm If you want the error bars to represent a given number C of standard errors instead of a confidence interval, and if the number of observations assigned to each