The cost of a long-distance phone call is a function of the length of the call in minutes. If the costs of the four calls shown in the table are graphed with minutes on the horizontal axis and cost on the vertical axis, what does the slope
of the graph represent?
O A rate of $0.13 per minute
O An average time of 5 minutes
between calls
O The total cost per call
An average of 12.5 minutes per call