The exponential function g is defined by g x = 19 · a x , where

The correct answer is $\mathrm{11,875}$. It's given that the exponential function $g$ is defined by $g\left(x\right)=19/mo><msup><mi>a</mi><mi>x</mi></msup>$, where $a$ is a positive constant, and $g\left(3\right)=\mathrm{2,375}$. It follows that when $x=3$, $g\left(x\right)=\mathrm{2,375}$. Substituting $3$ for $x$ and $\mathrm{2,375}$ for $g\left(x\right)$ in the given equation yields $\mathrm{2,375}=19/mo><msup><mi>a</mi><mn>3</mn></msup>$. Dividing each side of this equation by $19$ yields $125=a^3$. Taking the cube root of both sides of this equation gives $a=5$. Substituting $4$ for $x$ and $5$ for $a$ in the equation $g\left(x\right)=19/mo><msup><mi>a</mi><mi>x</mi></msup>$ yields $g\left(4\right)=19/mo><msup><mn>5</mn><mn>4</mn></msup>$, or $g\left(4\right)=11,875$. Therefore, the value of $g\left(4\right)$ is $\mathrm{11,875}$.