#### Answer

Widest to narrowest:
$f(x) = -\frac{2}{3}x^2$
$f(x) = -2x^{2}$
$f(x) = -4x^{2}$

#### Work Step by Step

If the coefficient of the function is greater than 1 or less than -1, the graph is more narrow, due to a vertical stretch. However, if the coefficient of the graph is between -1 and 1, the graph is wider, because of a vertical compression. Therefore, if the coefficient is larger, the graph is more narrow. If there coefficient is smaller, the graph is wider.