Homework Sourseneed help with this Q refer to the Chemosphere Feb 1986 stud
need help with this Q: refer to the Chemosphere (Feb 1986) study to obtain the background level of the toxic substance polychlorinated biphenyl (PCB) in soil samples in the United Kingdom. Such information is used as a benchmark against which PCB levels at the waste disposal facilities in the UK can be compared. The data table PCBUK contains the measured PCB levels of soil samples taken at 14 rural and 15 urban locations.(PCB is measured in .0001 gram per kilogram)
Construct stem and leaf plots for the PCB levels in rural and urban soil samples and discuss if there are any differences.
| Location | PCBLevel |
| 1 | 3.5 |
| 1 | 8.1 |
| 1 | 1.8 |
| 1 | 9 |
| 1 | 1 |
| 1 | 5.3 |
| 1 | 9.8 |
| 1 | 15 |
| 1 | 1.6 |
| 1 | 23 |
| 1 | 1.5 |
| 1 | 12 |
| 1 | 8.2 |
| 1 | 9.7 |
| 2 | 24 |
| 2 | 29 |
| 2 | 16 |
| 2 | 21 |
| 2 | 11 |
| 2 | 49 |
| 2 | 22 |
| 2 | 13 |
| 2 | 107 |
| 2 | 94 |
| 2 | 141 |
| 2 | 11 |
| 2 | 18 |
| 2 | 12 |
| 2 | 18 |
Solution
Location 1
Stem
Leaf unit =0.1
1
0 5 6 8
2
3
5
4
5
3
6
7
8
1 2
9
0 7 8
10
11
12
0
13
14
15
0
16
17
18
19
20
21
22
23
0
Location 2
Stem
Leaf unit 1
1
1 1 2 3 6 8 8
2
1 2 4 9
3
4
9
5
6
7
8
9
4
10
7
11
12
13
14
1
Location 1 range from 1 to 23 with decimal scores and location2 ranges from 11 to 141.
Location 1 data are around 1 and 8-9. The location 2 data is negatively skewed and spread is more.
Location1
Location2
n
14
15
mean
7.821
39.07
sample standard deviation
6.170
40.95
sample variance
38.071
1,676.78
minimum
1
11
maximum
23
141
range
22
130
| Stem | Leaf unit =0.1 |
| 1 | 0 5 6 8 |
| 2 | |
| 3 | 5 |
| 4 | |
| 5 | 3 |
| 6 | |
| 7 | |
| 8 | 1 2 |
| 9 | 0 7 8 |
| 10 | |
| 11 | |
| 12 | 0 |
| 13 | |
| 14 | |
| 15 | 0 |
| 16 | |
| 17 | |
| 18 | |
| 19 | |
| 20 | |
| 21 | |
| 22 | |
| 23 | 0 |
