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|
The Calculation of X2
Mather, K. 1963. Measurement of Linkage in Heredity. John
Wiley and Sons, New York, pgs. 24-25.
| The general formula is: |
x2= S |
(a-mn)2 |
|
| mn |
|
where a and mn are the observed and expected numbers in any
class.” “For a family segregating into two classes, whose
expected ratio is L:1,
and the observed numbers are a1:a2
The special cases of this formula for the more usual genetical
expectations are:”
| Ratio |
Formula |
| 1:1 |
1 |
(a1-a2)2 |
n |
| 3:1 |
1
|
(a1-3a2)2 |
3n |
| 15:1 |
1
|
(a1-15a2)2 |
15n |
| 1:3 |
1
|
(3a1-a2)2 |
3n |
| 9:7 |
7
|
(a1- (9/7)a2)2 |
9n |
Copyright
2000©, Ted Helms |
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