A Population Is Increasing According to the Exponential Function Defined $\mathrm { y } = 3 \mathrm { e } .04 \mathrm { x }$

Multiple Choice

A population is increasing according to the exponential function defined by $\mathrm { y } = 3 \mathrm { e } .04 \mathrm { x }$ , where $\mathrm { y }$ is in millions and $x$ is the number of years. Which of the following should be done in order to answer the question "How long will it take for the population to quadruple?"

A) Evaluate $\mathrm { y } = 3 \mathrm { e } \cdot 04 ( 4 )$ .
B) Solve $3 \mathrm { e } ^ { - 04 \mathrm { x } } = 4$ .
C) Evaluate $y = 3 e ^ { 0 } 04 ( 1 / 4 )$ .
D) Solve $3 e ^ { . } 04 x = 12$ .