The problem states that the cost for manufacturing $n$ desks is $C$ dollars, where $C = f(n)$. We need to determine the best interpretation of $f(n+4)$.

1. Problem Description

The problem states that the cost for manufacturing $n$ desks is $C$ dollars, where $C = f(n)$. We need to determine the best interpretation of $f(n+4)$.

2. Solution Steps

The expression $f(n)$ represents the cost of manufacturing $n$ desks. The expression $f(n+4)$ represents the cost of manufacturing $n+4$ desks.

Therefore, $f(n+4)$ means that we are calculating the cost of manufacturing $n+4$ desks, which is the same as manufacturing an additional 4 desks compared to manufacturing $n$ desks.

3. Final Answer

The cost, in dollars, of manufacturing an additional 4 more desks.