Answer
The vertex of the parabola is: $(15.22,2.54)$
Work Step by Step
Using the formula in finding the vertex of the given equation $y=-0.009t^2+0.274t+0.458$:
$$t=-\frac{b}{2a}=-\frac{0.274}{2(-0.009)}=15.22$$ Finding $y$:
$$y=-0.009(15.22)^2+0.274(15.22)+0.458=2.54$$
Thus, the vertex of the parabola is: $$(15.22,2.54)$$
