Answer
Maximum height: $13.6ft$
Work Step by Step
$y=-0.004x^2 + 0.037x +5$
Vertex formula: $(\frac{-b}{2a}, f(\frac{-b}{2a}))$
$\frac{-b}{2a}= \frac{-0.37}{2(-0.004)}= 46.25$
$f(\frac{-b}{2a}) = ((-0.004) \times (46.25^2)) + (0.037 \times 46.25) + 5 = 13.55625 $
Maximum height: $13.6ft$