Chapter 9 - Section 9.4 - Logistic Functions and Models - Exercises - Page 667: 19

$f(x)=\displaystyle \frac{98}{1+2.2(0.942)^{-x}}$ .

In desmos.com, we add a table with variables $x_{1}$ and $y_{1}$ and enter the given points. In the next free cell we enter $y_{1}\sim N/(1+Ab^{-x_{1}})$ and the calculator returns $N=97.6805$: we round to $98$ $A=2.2427 $: we round to $2.2$ $b=0.941936 $: we round to $0.942$ $f(x)=\displaystyle \frac{98}{1+2.2(0.942)^{-x}}$