Science Math Question (Basic)

**cdcox** · 03-29-2011, 12:16 AM

The real tragedy is that with two data points they can't even be sure that they've selected the correct population growth model.

Obviously they chose a linear growth model:

dP/dt = k

But their estimates would be different if they had chosen a geometric growth model:

dP/dt = kP

or a decreasing rate of increasing progression model:

dp/dt = k (Z-P)

You'd need at least three data points to accurately select the correct model. Taken together the three models make the classic S-shaped population curve (Geometric -> Linear -> Decreasing Rate). Any of the three models might be applicable, depending on the amount of resources available relative to the population, demographics, and social attitudes. Also, none of these models should be used to project populations more than 10 years into the future.

Did they mention these factors in their report?

03-29-2011, 12:16 AM	#19
cdcox www.nfl-forecast.com Join Date: Sep 2000 Casino cash: $-618231	The real tragedy is that with two data points they can't even be sure that they've selected the correct population growth model. Obviously they chose a linear growth model: dP/dt = k But their estimates would be different if they had chosen a geometric growth model: dP/dt = kP or a decreasing rate of increasing progression model: dp/dt = k (Z-P) You'd need at least three data points to accurately select the correct model. Taken together the three models make the classic S-shaped population curve (Geometric -> Linear -> Decreasing Rate). Any of the three models might be applicable, depending on the amount of resources available relative to the population, demographics, and social attitudes. Also, none of these models should be used to project populations more than 10 years into the future. Did they mention these factors in their report?
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