Choose the Logistic Function That Best Approximates the Curve $f ( x ) = \frac { 18 } { 1 + 2 ( 1.1 ) ^ { - x } }$

Multiple Choice

Choose the logistic function that best approximates the curve.

A) $f ( x ) = \frac { 18 } { 1 + 2 ( 1.1 ) ^ { - x } }$
B) $f ( x ) = \frac { 18 } { 2 + 2 ( 4 ) ^ { - x } }$
C) $f ( x ) = \frac { 18 } { 2 + 7 ( 1.1 ) ^ { - x } }$
D) $f ( x ) = \frac { 18 } { 1 + 7 ( 1.1 ) ^ { - x } }$
E) $f ( x ) = \frac { 18 } { 2 + 7 ( 4 ) ^ { - x } }$