To find the unit cost of each boxed lunch, we'll divide the total cost by the number of boxed lunches ordered.
The total cost is $208.75 and the number of boxed lunches is 25.
Using the formula:
\[ \text{Unit Cost} = \frac{\text{Total Cost}}{\text{Number of Boxed Lunches}} \]
we can substitute the values:
\[ \text{Unit Cost} = \frac{208.75}{25} \]
Now, performing the division:
\[ \text{Unit Cost} = 8.35 \]
Therefore, the unit cost of each boxed lunch is $8.35.