assume that the bp rig in the gulf of mexico has four major safety devices all connected in a series. the corresponding reliabilities of these four devices are: device 1: 0.85 device 2: 0.95 device 3: 0.80 device 4: 0.80 device 2 has a single backup system with identical reliability. device 3 has a single backup system that has two subcomponents (each with a reliability of .50) that are connected in a series. device 4 is backed up by two backup systems (each with reliability of .75). what is the likelihood that these safety devices (working together) will prevent another disaster?