To write the cost function $C(x)$, where $x$ is the number of copies of the newspaper produced and sold, we need to account for two parts:

1. Fixed costs: These are costs that do not change with the number of copies produced. In this case, the fixed production costs are $74 per edition.

2. Variable costs: These are costs that vary with the number of copies. The marginal printing and distribution costs are given as 39¢ per copy, which is $0.39 per copy.

Thus, the total cost function $C(x)$ can be expressed as: $C(x) = 74 + 0.39x$ Where:

• $74$ is the fixed cost in dollars,
• $0.39x$ represents the variable cost for $x$ copies.

This cost function accounts for both fixed production costs and variable costs depending on the number of copies printed.

Let me know if you'd like further details or clarification! Here's a list of related questions:

1. What would the cost function look like if the fixed production costs were higher?
2. How do the fixed and variable costs affect the price point for the newspaper?
3. If the number of copies sold increases, how does that affect total costs?
4. What would be the total cost if 500 copies were printed?
5. How can you calculate profit from the cost and revenue functions?

Tip: The total cost function helps in understanding how the overall production costs are influenced by the number of units produced.