Biology Webb and colleagues $^{24}$ created a mathematical model that showed that the population $y$ of gypsy moths was approximated by $y=f(x)=10^{3.8811-0.1798 \sqrt{x}},$ where $x$ was the dose in grams per hectare of the insecticide racemic disparlure. Find $f^{\prime}(x),$ and determine whether this function is decreasing. Sketch a graph. What happens if the dose $x$ becomes very large?