Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Raw data Listing
Obs
TIME
VOLTAGE
GROUP
LogTime
1
5.79
26
GROUP 1
1.75613
2
1579.52
26
GROUP 1
7.36488
3
2323.70
26
GROUP 1
7.75092
4
68.85
28
GROUP 2
4.23193
5
108.29
28
GROUP 2
4.68481
6
110.29
28
GROUP 2
4.70311
7
426.07
28
GROUP 2
6.05460
8
1067.60
28
GROUP 2
6.97317
9
7.74
30
GROUP 3
2.04640
10
17.05
30
GROUP 3
2.83615
11
20.46
30
GROUP 3
3.01847
12
21.02
30
GROUP 3
3.04547
13
22.66
30
GROUP 3
3.12060
14
43.40
30
GROUP 3
3.77046
15
47.30
30
GROUP 3
3.85651
16
139.07
30
GROUP 3
4.93498
17
144.12
30
GROUP 3
4.97065
18
175.88
30
GROUP 3
5.16980
19
194.90
30
GROUP 3
5.27249
20
0.27
32
GROUP 4
-1.30933
21
0.40
32
GROUP 4
-0.91629
22
0.69
32
GROUP 4
-0.37106
23
0.79
32
GROUP 4
-0.23572
24
2.75
32
GROUP 4
1.01160
25
3.91
32
GROUP 4
1.36354
26
9.88
32
GROUP 4
2.29051
27
13.95
32
GROUP 4
2.63548
28
15.93
32
GROUP 4
2.76820
29
27.80
32
GROUP 4
3.32504
30
53.24
32
GROUP 4
3.97481
31
82.85
32
GROUP 4
4.41703
32
89.29
32
GROUP 4
4.49189
33
100.59
32
GROUP 4
4.61105
34
215.10
32
GROUP 4
5.37110
35
0.19
34
GROUP 5
-1.66073
36
0.78
34
GROUP 5
-0.24846
37
0.96
34
GROUP 5
-0.04082
38
1.31
34
GROUP 5
0.27003
39
2.78
34
GROUP 5
1.02245
40
3.16
34
GROUP 5
1.15057
41
4.15
34
GROUP 5
1.42311
42
4.67
34
GROUP 5
1.54116
43
4.85
34
GROUP 5
1.57898
44
6.50
34
GROUP 5
1.87180
45
7.35
34
GROUP 5
1.99470
46
8.01
34
GROUP 5
2.08069
47
8.27
34
GROUP 5
2.11263
48
12.06
34
GROUP 5
2.48989
49
31.75
34
GROUP 5
3.45789
50
32.52
34
GROUP 5
3.48186
51
33.91
34
GROUP 5
3.52371
52
36.71
34
GROUP 5
3.60305
53
72.89
34
GROUP 5
4.28895
54
0.35
36
GROUP 6
-1.04982
55
0.59
36
GROUP 6
-0.52763
56
0.96
36
GROUP 6
-0.04082
57
0.99
36
GROUP 6
-0.01005
58
1.69
36
GROUP 6
0.52473
59
1.97
36
GROUP 6
0.67803
60
2.07
36
GROUP 6
0.72755
61
2.58
36
GROUP 6
0.94779
62
2.71
36
GROUP 6
0.99695
63
2.90
36
GROUP 6
1.06471
64
3.67
36
GROUP 6
1.30019
65
3.99
36
GROUP 6
1.38379
66
5.35
36
GROUP 6
1.67710
67
13.77
36
GROUP 6
2.62249
68
25.50
36
GROUP 6
3.23868
69
0.09
38
GROUP 7
-2.40795
70
0.39
38
GROUP 7
-0.94161
71
0.47
38
GROUP 7
-0.75502
72
0.73
38
GROUP 7
-0.31471
73
0.74
38
GROUP 7
-0.30111
74
1.13
38
GROUP 7
0.12222
75
1.40
38
GROUP 7
0.33647
76
2.38
38
GROUP 7
0.86710
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Plot of the raw data
Plot of TIME*VOLTAGE. Legend: A = 1 obs, B = 2 obs, etc.
TIME |
|
2500 +
|
| A
|
|
|
2000 +
|
|
|
|
| A
1500 +
|
|
|
|
| A
1000 +
|
|
|
|
|
500 +
| A
|
| A
| D
| C B D A
0 + A E J R O H
|
---+--------------+--------------+--------------+--------------+--------------+--------------+--
26 28 30 32 34 36 38
VOLTAGE
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Initial fit of the raw data
Simple Regression with REG
The REG Procedure
Model: MODEL1
Dependent Variable: TIME
Number of Observations Read
76
Number of Observations Used
76
Analysis of Variance
Source
DF
Sum of Squares
Mean Square
F Value
Pr > F
Model
1
2150408
2150408
24.27
<.0001
Error
74
6557345
88613
Corrected Total
75
8707754
Root MSE
297.67898
R-Square
0.2470
Dependent Mean
98.55776
Adj R-Sq
0.2368
Coeff Var
302.03504
Parameter Estimates
Variable
DF
Parameter Estimate
Standard Error
t Value
Pr > |t|
Intercept
1
1886.16945
364.48121
5.17
<.0001
VOLTAGE
1
-53.95492
10.95264
-4.93
<.0001
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Initial fit of the raw data
Plot of residuals
Plot of resid*VOLTAGE. Legend: A = 1 obs, B = 2 obs, etc.
resid |
2000 +
|
| A
|
|
|
1500 +
|
|
|
|
| A
1000 +
|
|
|
| A
|
500 +
|
|
|
| H
| A A O
0 +----------------------------------------------------------F------------------------------
| C D M
| A J
| B G
| A
|
-500 + A
|
---+-------------+-------------+-------------+-------------+-------------+-------------+--
26 28 30 32 34 36 38
VOLTAGE
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Initial fit of the raw data
Plot of residuals
Plot of resid*YHat. Legend: A = 1 obs, B = 2 obs, etc.
resid |
2000 +
|
| A
|
|
|
1500 +
|
|
|
|
| A
1000 +
|
|
|
| A
|
500 +
|
|
|
| H
| O A A
0 +------------------------------F----------------------------------------------------------
| M D C
| J A
| G B
| A
|
-500 + A
|
---+-------------+-------------+-------------+-------------+-------------+-------------+--
-164.12 -56.21 51.70 159.61 267.52 375.43 483.34
YHat
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Initial fit of the raw data
Plot of residuals
The UNIVARIATE Procedure
Variable: resid
Moments
N
76
Sum Weights
76
Mean
0
Sum Observations
0
Std Deviation
295.687792
Variance
87431.2704
Skewness
4.02671557
Kurtosis
21.9169395
Uncorrected SS
6557345.28
Corrected SS
6557345.28
Coeff Variation
.
Std Error Mean
33.9177159
Basic Statistical Measures
Location
Variability
Mean
0.0000
Std Deviation
295.68779
Median
-46.0272
Variance
87431
Mode
.
Range
2318
Interquartile Range
203.20468
Tests for Location: Mu0=0
Test
Statistic
p Value
Student's t
t
0
Pr > |t|
1.0000
Sign
M
-9
Pr >= |M|
0.0505
Signed Rank
S
-283
Pr >= |S|
0.1440
Tests for Normality
Test
Statistic
p Value
Shapiro-Wilk
W
0.615009
Pr < W
<0.0001
Kolmogorov-Smirnov
D
0.248565
Pr > D
<0.0100
Cramer-von Mises
W-Sq
1.204042
Pr > W-Sq
<0.0050
Anderson-Darling
A-Sq
6.998223
Pr > A-Sq
<0.0050
Quantiles (Definition 5)
Quantile
Estimate
100% Max
1840.3584
99%
1840.3584
95%
166.4975
90%
164.8475
75% Q3
58.5327
50% Median
-46.0272
25% Q1
-144.6720
10%
-246.5019
5%
-265.1417
1%
-477.5515
0% Min
-477.5515
Extreme Observations
Lowest
Highest
Value
Obs
Value
Obs
-477.552
1
165.518
75
-306.582
4
166.498
76
-267.142
5
692.168
8
-265.142
6
1096.178
2
-259.782
9
1840.358
3
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Examination of the log transformed data
Plot of the log transformed data
Plot of LogTime*VOLTAGE. Legend: A = 1 obs, B = 2 obs, etc.
LogTime |
|
8 +
| A
| A
| A
|
|
6 + A
|
| B A
| B
| B A
| A B A
4 + A A
| A B
| A B A
| D
| B A
| A A
2 + A D
| A B A
| A A B
| A B C A
| C
| A A
0 + A B A
| B A B
| A A
| A A A
| A
| A
-2 +
| A
|
|
|
|
-4 +
|
---+-------------+-------------+-------------+-------------+-------------+-------------+--
26 28 30 32 34 36 38
VOLTAGE
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Examination of the log transformed data
Transformed regression with REG
The REG Procedure
Model: MODEL1
Dependent Variable: LogTime
Number of Observations Read
76
Number of Observations Used
76
Analysis of Variance
Source
DF
Sum of Squares
Mean Square
F Value
Pr > F
Model
1
190.15149
190.15149
78.14
<.0001
Error
74
180.07484
2.43344
Corrected Total
75
370.22633
Root MSE
1.55995
R-Square
0.5136
Dependent Mean
2.14566
Adj R-Sq
0.5070
Coeff Var
72.70267
Parameter Estimates
Variable
DF
Parameter Estimate
Standard Error
t Value
Pr > |t|
Intercept
1
18.95546
1.91002
9.92
<.0001
VOLTAGE
1
-0.50736
0.05740
-8.84
<.0001
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Examination of the log transformed data
Plot of residuals
Plot of resid*VOLTAGE. Legend: A = 1 obs, B = 2 obs, etc.
resid |
|
4 +
|
|
|
| A A A
| A
2 + A A A A
| A A B C
| A C A A
| A
| A A B A
| D C A
0 +----------------B-------------B-------------B-------------B-------------C-------------B--
| A A A
| A C B B A
| A
| A A A
| A A A A
-2 + A A
|
|
| B
| A
| A
-4 + A A
|
---+-------------+-------------+-------------+-------------+-------------+-------------+--
26 28 30 32 34 36 38
VOLTAGE
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Examination of the log transformed data
Plot of residuals
Plot of resid*YHat. Legend: A = 1 obs, B = 2 obs, etc.
resid |
|
4 +
|
|
|
| A A A
| A
2 + A A A A
| C B A A
| A A C A
| A
| A B A A
| A C D
0 +--B-------------C-------------B-------------B-------------B-------------B----------------
| A A A
| A B B C A
| A
| A A A
| A A A A
-2 + A A
|
|
| B
| A
| A
-4 + A A
|
---+-------------+-------------+-------------+-------------+-------------+-------------+--
-0.324 0.690 1.705 2.720 3.735 4.749 5.764
YHat
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid
Examination of the log transformed data
Plot of residuals
The UNIVARIATE Procedure
Variable: resid
Moments
N
76
Sum Weights
76
Mean
0
Sum Observations
0
Std Deviation
1.54951535
Variance
2.40099782
Skewness
-0.6488654
Kurtosis
0.30321576
Uncorrected SS
180.074836
Corrected SS
180.074836
Coeff Variation
.
Std Error Mean
0.1777416
Basic Statistical Measures
Location
Variability
Mean
0.000000
Std Deviation
1.54952
Median
0.036589
Variance
2.40100
Mode
.
Range
6.68044
Interquartile Range
1.91300
Tests for Location: Mu0=0
Test
Statistic
p Value
Student's t
t
0
Pr > |t|
1.0000
Sign
M
3
Pr >= |M|
0.5666
Signed Rank
S
93
Pr >= |S|
0.6333
Tests for Normality
Test
Statistic
p Value
Shapiro-Wilk
W
0.956759
Pr < W
0.0112
Kolmogorov-Smirnov
D
0.10799
Pr > D
0.0267
Cramer-von Mises
W-Sq
0.11647
Pr > W-Sq
0.0699
Anderson-Darling
A-Sq
0.834933
Pr > A-Sq
0.0311
Quantiles (Definition 5)
Quantile
Estimate
100% Max
2.6513227
99%
2.6513227
95%
2.2239282
90%
1.8912724
75% Q3
1.2183016
50% Median
0.0365886
25% Q1
-0.6947034
10%
-1.9535119
5%
-3.3657817
1%
-4.0291137
0% Min
-4.0291137
Extreme Observations
Lowest
Highest
Value
Obs
Value
Obs
-4.02911
20
1.98695
3
-4.00784
1
2.22393
8
-3.63607
21
2.54836
68
-3.36578
35
2.58390
53
-3.09084
22
2.65132
34
Chapter 8 : Time to breakdown of 76 samples of an insulating fluid