Price holding all else constant. To model the population at any arbitrary year we rewrite the exponential function in terms of the doubling time. Exponential Growth And Doubling Time Nsta A₀ is the initial amount h is the half life time or the halving time. . Every twelve years the population doubles and the exponent becomes an integer based on nt12. Ft300cdot 2t12 or more generally ft300cdot 2tT where T is the doubling time. We have a function of the form ft A3tT and you can see that. As y doubles proportionately to x. Radioactive decay is a good example where the half life is constant over the entire decay time. Exponential growth O c. Holding all else constant. It is proved in calculus that this law requires that the quantity is given by the exponential function if we use the correct time scale. If you dont know your growth rate you can derive it by subtracting your past quantity from your current quant...