To rotate a point \((x, y)\) about the origin by \(270^\circ\) counterclockwise, we can use the following transformation rules:
\[ (x, y) \rightarrow (y, -x) \]
Now, applying this transformation to point \(M(0, 4)\):
- Identify the coordinates of \(M\): \(x = 0\), \(y = 4\).
- Apply the transformation:
\[ M' = (y, -x) = (4, -0) = (4, 0) \]
Therefore, the image of point \(M\) after the \(270^\circ\) rotation about the origin is:
\[ M' (4, 0) \]