Answer:
2,276
Explanation:
The problem statement tells us that for b books, ...
production cost = 21053 +9.50b
sales = 18.75b
For these to be equal, we must have ...
production cost = sales
21053 +9.50b = 18.75b . . . . . substitute the expressions
21053 = 9.25b . . . . . . . . . . . . subtract 9.50*
21053/9.25 = b = 2276
The publisher must produce and sell 2,276 books to break even.
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* The value 9.25 is sometimes called the "contribution margin" of the book. It is the excess of the marginal sales over the marginal cost. As we see, dividing the fixed costs by this amount tells the number of sales required to break even, earn a total profit of zero, cover costs.