Page 243 - Applied statistics and probability for engineers

Section 6-5/Time Sequence Plots 221

Leaf Stem Time series plot
8 9e
6 9s
45 9f
2333 9t
FIGURE 6-18 A 0010000 9z
digidot plot of 99998 8e
8s
66677
chemical process 45 8f
concentration 23 8t
readings, observed 1 8z
hourly.

Exercises FOR SECTION 6-5

Problem available in WileyPLUS at instructor’s discretion.
Tutoring problem available in WileyPLUS at instructor’s discretion.

6-82. The following data are the viscosity measurements 16.3 17.2 17.4 17.5 16.5
for a chemical product observed hourly (read down, then left to 16.1 17.4 17.5 17.4 17.8
right). Construct and interpret either a digidot plot or a separate 17.1 17.4 17.4 17.4 17.3
stem-and-leaf and time series plot of these data. Speciications 16.9 17.0 17.6 17.1 17.3
on product viscosity are at 48 ± 2. What conclusions can you 16.8 17.3 17.4 17.6 17.1
make about process performance? 17.4 17.2 17.3 17.7 17.4
17.1 17.4 17.0 17.4 16.9
47.9 48.6 48.0 48.1 43.0 43.2
17.0 16.8 17.8 17.8 17.3
47.9 48.8 47.5 48.0 42.9 43.6
48.6 48.1 48.6 48.3 43.6 43.2 Construct and interpret either a digidot plot or a separate stem-
48.0 48.3 48.0 43.2 43.3 43.5 and-leaf and time series plot of these data.
48.4 47.2 47.9 43.0 43.0 43.0 6-85. The 100 annual Wolfer sunspot numbers from 1770 to
48.1 48.9 48.3 43.5 42.8 1869 follow. (For an interesting analysis and interpretation of these
48.0 48.6 48.5 43.1 43.1 numbers, see the book by Box, Jenkins, and Reinsel referenced in
Exercise 6-84. Their analysis requires some advanced knowledge
6-83. The pull-off force for a connector is measured in a
of statistics and statistical model building.) Read down, then left to
laboratory test. Data for 40 test specimens follow (read down,
right. The 1869 result is 74. Construct and interpret either a digidot
then left to right). Construct and interpret either a digidot plot
plot or a stem-and-leaf and time series plot of these data.
or a separate stem-and-leaf and time series plot of the data.
101 31 154 38 83 90
241 203 201 251 236 190
82 7 125 23 132 67
258 195 195 238 245 175
66 20 85 10 131 60
237 249 255 210 209 178 35 92 68 24 118 47
210 220 245 198 212 175 41 10 16 8 62 94
21 8 7 13 98 96
194 194 235 199 185 190
16 2 4 57 124 77
225 245 220 183 187
6 0 2 122 96 59
248 209 249 213 218 4 1 8 138 66 44
7 5 17 103 64 47
6-84. In their book Time Series Analysis, Forecasting, and
14 12 36 86 54 30
Control (Prentice Hall, 1994), G. E. P. Box, G. M. Jenkins, and
34 14 50 63 39 16
G. C. Reinsel present chemical process concentration readings
45 35 62 37 21 7
made every two hours. Some of these data follow (read down,
43 46 67 24 7 37
then left to right).
48 41 71 11 4 74
17.0 16.7 17.1 17.5 17.6 42 30 48 15 23
16.6 17.4 17.4 18.1 17.5 28 24 28 40 55