Water jug: If a completely full 5-gallon water jug is drained through a spigot, the depth is given by the formula where t is the time, in minutes, that the spigot is open and D is the depth, in...

Water jug: If a completely full 5-gallon water jug is drained through a spigot, the depth is given by the formula

where t is the time, in minutes, that the spigot is open and D is the depth, in inches, above the spigot.

a. Make a graph of D versus t. Include values of t up to 7.5 minutes.

b. Calculate D(3) and explain in practical terms what your answer means.

c. When will the water jug be completely drained?

d. Does the water drain faster near the beginning or when the water is mostly drained?