Mean sea level Mean sea level has very little variability across all ocean basins and, therefore, is treated as an absolute value. is based on average tidal levels recorded hourly at a given site over a period of many years. is a consistent value yet to be determined due to the variables involved in producing the tides. is constant enabling scientist to determine a single value thereof, though there are local minor variations. is at the same level along the entire North American coast.

Efficient homemakers ltd. makes canvas wallets and leather wallets as part of a money-making project. for the canvas wallets, they need two yards of canvas and two yards of leather. for the leather wallets, they need four yards of leather and three yards of canvas. their production unit has purchased 44 yards of leather and 40 yards of canvas. let x be the number of leather wallets and y be the number of canvas wallets. draw the graph showing the feasible region to represent the number of the leather and canvas wallets that can be produced.