Beth Nelson, who owns and runs a small sporting goods store, buys most of her merchandise directly from manufacturers. Ms. Nelson was shocked at the $7.50 charge for a container of three ping-pong balls. She found it hard to believe that it could have cost more than $1.00 to make the balls. When she complained to Jim Wilson, the marketing manager of the manufacturing company, he tried to explain that the cost also included companywide overhead costs. How could companywide overhead affect the cost of ping-pong balls?