In our widget example, we will assume that the fixed cost for the stapler, pen, and âfactoryâ is $10 and the cost of each worker hired is $5 per worker. Since fixed costs are constant, the firm incurs $10 regardless of the level of output. Labor is the only variable cost computed by $5 times the number of workers.
How Bull Sharks Can Live in Both Ocean and Fresh Water. Although there are a handful of species that live in freshwater, we tend to think of sharks as being ocean dwellers. But there is also a very unique shark that can live in both ocean and fresh water estuaries and lakes: the Bull Shark.
All the species you will see at the Newport Aquarium live in saltwater, but some species are able to live in freshwater too. Eighty percent of sharks are smaller than the average human, and only a dozen species have been known to attack humans. Our sharks are fed one to three times per week, depending on the species.