Petersen capture-recapture formula (Edexcel GCSE Statistics): Flashcards
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7 cards from this deck
Find N: M=60, n=40, m=6
Find N: M=60, n=40, m=6
N=(60×40)/6=400
Estimate N: M=80, n=40, m=40
Estimate N: M=80, n=40, m=40
N=(80×40)/40=80
Give 3 key assumptions of method
Give 3 key assumptions of method
Closed pop.; equal catchability; marks stay visible
If marking reduces recapture chance, effect on N?
If marking reduces recapture chance, effect on N?
m decreases → N increases; population overestimated
Name two critical assumptions
Name two critical assumptions
Closed population; equal catchability
Estimate N when M=60, n=40, m=6
Estimate N when M=60, n=40, m=6
N = 60×40÷6 = 400
Estimate N from M=60, n=40, m=6
Estimate N from M=60, n=40, m=6
N = (60×40)/6 = 400