Page 132 - Statistics and Data Analysis in Geology

Spatial Analysis

to sum to 160, and a second degree of freedom is required for estimation of the
parameter A). For c = 5 categories, there are three degrees of freedom.

Figure 5-6. Locations of oil-field discovery wells in part of the Eastern Shelf area of the
Permian Basin, Fisher and Noland counties, Texas. Quadrats are approximately 10
mi2 in size.

Table 5-2. Calculation of expected numbers of tracts containing Y discoveries
in eastern part of Permian Basin, Texas, assuming a Poisson distribution.
Number of Number of Tracts
Discoveries Tract Contains
Per Tract (Y) Poisson Eauation Y Discoveries mected Observed

0 q0) e(-1.05)1.050 0.3499 56.0 70
=
O!
1 p(l) = e(-1.05).!& l! 0.3674 58.8 42
2 p(2) = e(-1.05)* 2! 0.1929 30.9 26
3 p(3) = e(-1.05)W 0.0675 10.8 17
3!
4 q4) e(-1.05)1.054 4! 0.0177 2.8 3
=
5 q5) e(-1.05)1.055 0.0037 0.6 1
=
5!
6 p(@ = e(-1.05)1.056 0.0007 0.1 __ 1
6!
TOTALS 0.9998 160.0 160

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