A carpenter charges a fixed rate for

each hour of labor. Let’s describe this

rate as a function of time by r(t) = 25,

where t is measured in hours and r is

measured in dollars per hour. Draw the

graph of r versus t. Be sure to label each

axis with appropriate units. Shade the

area under the graph of r over the time

interval [0, 5] hours. What is the area under the graph of r over this time interval

and what does it represent?