Answer:
3.2 feet
Step-by-step explanation:
The equation [tex]f(x)=-0.3x^{2}+2x[/tex] shows the height of water [[tex]f(x)[/tex]] and horizontal distance [[tex]x[/tex]].
Given the horizontal distance is 4 feet, they want to know the height.
Simply put 4 in [tex]x[/tex] of the equation and solve for [tex]f(x)[/tex]. So,
[tex]f(x)=-0.3(4)^{2}+2(4)\\f(x)=3.2[/tex]
So, the height of the water was 3.2 feet above the ground.