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BTRY 601
Solutions, Homework #7
Fall 2005
Due Friday, 11/04/2005 before class
Name (
last name first
, upper case letters)______________________________
General Guidelines:
9
Write down your name above (use upper case letters)
9
Check your computer lab # in the table below.
9
Make sure to type your solutions.
9
Please use JMP for data analysis (as necessary) and only attach relevant
output to each question.
This cover page must be
stapled to each homework assignment you turn
in. It is the front page of your homework.
Please, check your lab section in the space provided below
(Column #1).
Lab #
Day
Time
Location
TA
1_____
Monday
07300845PM
WN160
Matthias Kormaksson
2_____
Monday
07300845PM
WN B60
Hong Gao
3 Canceled Tuesday
10101125AM
WN B60
4_____
Tuesday
08400955AM
WN B60
Elizabeth Schifano
5_____
Tuesday
02550410PM
WN B60
Michael Grabchak
6_____
Tuesday
02550410PM
RR 160
David Clement
7_____
Tuesday
07300845PM
WN 160
Michael Grabchak
8_____
Monday
03000415PM
RR 163
David Clement
Note:
Students’ solutions to a few selected questions are posted at
http://www.duxbury.com/statistics_d/
. A zipped file is available for
download. Students’ solutions are also posted on our course web site
and can be accessed by clicking on the Homework link.
Grading Sheet
Maximum Points
Obtained Points
100
1
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View Full Document BTRY 601
Solutions, Homework #7
Fall 2005
Unless otherwise indicated, use JMP to do the following exercises from
An
Introduction to Statistical Methods and Data Analysis (Ott and Longnecker, 5
th
Edition, 2004)
.
Please only attach the relevant portion of the output under
each subquestion whenever applicable
. For any unnecessary JMP output,
points will be deducted.
Exercise 8.6 (a), (b), (c), (d), p. 413:
8 points
(a) Graphical and statistical tests to assess adequacy of ANOVA conditions.
Yield
5
10
15
20
25
30
35
40
45
50
A
B
C
DE
Variety
Test
F Ratio
DF Num
DF Den
Pvalue
Levene
5.2143
4
30
0.0026
Bartlett
3.8782
4
.
0.0037
2
BTRY 601
Solutions, Homework #7
Fall 2005
The boxplots show that all varieties except E are rightskewed.
However, it is
difficult to assess normality with small sample sizes.
The normal probability
plot of residuals clearly indicates that the assumption of normality is satisfied (p
value = 0.1582).
The Levine’s (F = 5.2143, pvalue = 0.0026) and Bartlett’s (F = 3.8782,
pvalue = 0.0037) tests both yield highly significant unequal variances. Thus,
there are significant differences between the five varieties’ variances.
(b) Analysis of variance table.
Source of Variation
DF
SS
MS
Ftest
PValue
Varieties
4
1096.7429
274.18571
3.729693
0.014
Error
30
2205.4286
73.514286
0.0140359
C. Total
34
3302.1714
Reject
if
o
H
α
=≥
=
4,30
0.01,4,30
If pvalue <
0.01or if
4.017877
FF
.
Since
or since pvalue = 0.014 >
4,30
0.01,4,30
3.73
4.017877
=<
=
0.01
=
we fail to
reject
and conclude there are no significant differences between the mean
yield of the five varieties.
0
H
(c) The KruskalWallis yield
10.01
H
=
'
with pvalue = 0.04 >
0.01
=
.
Thus, fail
to reject
and conclude there is no significant difference in the distributions of
the yields for the five varieties.
o
H
ChiSquare
DF
Pvalue
10.0114254
4
0.04023566
(d) The only difference in the conclusions is that the pvalue for the Ftest is
somewhat smaller than the pvalue for the KruskalWallis test.
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This homework help was uploaded on 09/28/2007 for the course BTRY 6010 taught by Professor Wells,m. during the Fall '05 term at Cornell University (Engineering School).
 Fall '05
 WELLS,M.
 BTRY, mean control, DF Numerator DF

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