Four Fours/Lemmata/One Four/4 Ninths/Solutions/1

Puzzle: One Four: $\dfrac 4 9$

Using exactly $1$ instance of the number $4$, the task is to write an expression for $\dfrac 4 9$, using whatever arithmetical operations you consider necessary.

Solution

$\dfrac 4 9 = {. \dot 4}$