Question the-fu

The function $f\left(x\right)=55.20-0.16x$ gives the estimated surface water temperature $f\left(x\right)$, in degrees Celsius, of a body of water on the $x\text{th}$ day of the year, where $220\le x\le 360$. Based on the model, what is the estimated surface water temperature, in degrees Celsius, of this body of water on the $326\text{th}$ day of the year?