Suppose that an electronic system comprises four components, and let Xj denote the time until component j fails to operate (j = 1, 2, 3, 4). Suppose that Xl' x2 , X3, and X4 are Li.d. random variables, each of which has a continuous distribution with d.f. F(x). Suppose that the system will operate as long as both component 1 and at least one of the other three components operate. Determine the dJ. of the time until the system fails to operate.