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Table 3. Statistical interpretation of total nitrogen and total phosphorus concentrations at the east coast canal sites in Miami-Dade County

[Significant level (a) = 0.05/2=0.025; P values from Helsel and Hirsch (1992, table B6); DI, depth integrated; >, greater than the value; N/A, not applicable]

Note: The superscript numbers in the table refer to the numbered explanations below
Site No.
Constituent
Statistical difference between samples
Grab samples collected at 1.0-meter depth and DI samples
Grab samples collected at 0.5-meter depth and DI samples
Grab samples collected at 0.5-meter and 1.0-meter depths
No. of sample pairs
No. of non-
zero differ-
ences
W+ statistic
P value
No. of samples
No. of non-
zero differ-
ences
W+ statistic
P value
No. of samples
No. of non-
zero differ-
ences
W+ statistic
P value
G-58
 Total nitrogen
6
4
3.5
>0.312
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
6
4
4
>.312
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
G-93
 Total nitrogen
10
8
15
>.191
4
3
4
.375
4
4
7.5
>0.188
Total phosphorus
10
2
1.5
>.375
4
0
0
>.375
4
1
1
>.375
S-21
 Total nitrogen
17
15
56
>.151
8
7
11
>.188
8
7
17.5
>.188
Total phosphorus
171
141
941
.0031
82
72
25.52
.0232
8
4
2
>.312
S-21A
 Total nitrogen
7
7
15
>.188
5
5
10
>.219
5
4
8
>.188
Total phosphorus
7
4
8
.188
5
1
1
>.375
5
4
2
>.312
S-22
 Total nitrogen
21
14
80
.045
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
21
7
14.5
>.188
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-25
 Total nitrogen
14
9
29
>.180
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
14
6
14
>.219
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-25B
 Total nitrogen
20
13
63
.122
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
203
103
553
.0013
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-26
 Total nitrogen
18
8
10.5
>.191
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
18
6
17
.109
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-27
 Total nitrogen
17
7
10.5
>.188
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
17
4
4
>.312
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-28
 Total nitrogen
18
11
44
>.160
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
184
64
214
.0164
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-29
 Total nitrogen
17
11
38.5
>.160
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
17
7
18
>.188
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
S-123
 Total nitrogen
7
6
19
.047
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Total phosphorus
7
4
10
.062
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A

Statistically Significant Differences Between Grab and Depth-Integrated Samples
1 Equation from line of organic correlation is Grab = 0.2973 DI + 0.0057. Direction of bias of grab is low.
2 Equation from line of organic correlation is Grab = 0.25 DI + 0.00625. Direction of bias of grab is low.
3 Equation from line of organic correlation is Grab = 0.8255 DI - 0.0018. Direction of bias of grab is low.
4 Equation from line of organic correlation is Grab = 1.093 DI - 0.008. Direction of bias of grab is low.

Statistical Comparisons of Point (Grab) and Depth-Integrated Samples


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Last updated: 19 January, 2005 @ 02:47 PM (KP)