If light bulbs failure times are identically and independently distributed, what shape would you expect for the hazard function of the light bulbs? Draw a picture and explain. It has been suggested that after the rst headlight in an automobile fails, both of the headlights should be replaced. Assume that the failure record makes known whether the replaced bulb is on the left or on the right of the car. Explain how you would analyze the available data to see if this is a good idea or not.