STAT 3504
Assignment #2
DUE: Wed. Feb. 9
Use SAS to help you do questions
#1, #2, #3, #4 & #5.
Hand in a copy of BOTH code and output.
Remember to use the
DM
and
FOOTNOTE statements at the beginning of your program.
Also use a
LINESIZE of
85
and a
PAGESIZE
of
35 or 40.
1.
#2 on assign 1 cont.
:
In an experiment to investigate the effect of colour of paper (blue, green,
orange) on response rates for questionnaires distributed by the "windshield" method in supermarket
parking lots,
15
representative supermarket parking lots were chosen in a metropolitan area and
each colour was assigned at random to
5
of the lots.
The response rates (in percent) follow.
Assume the fixed levels single factor ANOVA model
ε
μ
ij
i
ij
+
=
Y
is appropriate.
unit j
factor level i
1
2
3
4
5
blue
28
26
31
27
35
green
34
29
25
31
29
orange
33
25
27
29
28
N.B.
Since the sample sizes in the factor levels are small, instead of obtaining plots and tests for
each factor level, in order to check for nonnormality you should combine ALL the
e
ij

provided there is no evidence of inequality of variances
among the factor levels.
From
Assignment 1, the BrownForsythe test for unequal
factor level variances gave
8
1
.0
=
F
*
2)
(2,
BF
with a pvalue of
0.9192.
a)
Is it appropriate here to combine all the e
ij
?
Why or why not?
b)
Fit the model and test whether there is evidence of obvious nonnormality by
i)
use of a normal probability plot
and
ii)
using the correlation coefficient between the ordered residuals and their expected
values under normality with Table B6 to test for nonnormality.
2.
For problem #18.17 in your text the data is in the CD that comes with your text under the file name
ch18pr17.dat
It is also in
/CourseFiles/STAT3504A/ch18pr17.dat
column 1 = response,
column 2 = factor level (winding speeds),
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 Winter '10
 Ann
 Normal Distribution, factor level, ε ij

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