Atank contains 280 gallons of water and 10 oz of salt. water containing a salt concentration of -(1 + =sin t) oz/gal flows into the tank at a rate of 3 gal/min, and the mixture in the tank flows out at the same rate. the long-time behavior of the solution is an oscillation about a certain constant level. what is this level? what is the amplitude of the oscillation? round the values to two decimal places. oscillation about a level = oz. amplitude of the oscillation =