## Precalculus (6th Edition) Blitzer

Use the given model function $f(x)=\frac{12.57}{1+4.11e^{-0.026x}}$ For year 2000, we have $x=2000-1949=51$ and $f(51)=\frac{12.57}{1+4.11e^{-0.026(51)}}\approx6.01$ billion As this number is close to $6.1$ billion, the model fits the data very well.