This question is asking for the defect rate of the system. A certain assembly

line utilizes $4$ separate stations each with its own machine. The four machines have the

following listed reliabilities: Machine A: $0\mathrm{.}96,$ Machine B: $0\mathrm{.}97,$ Machine C: $0\mathrm{.}86,$ Machine

D: $0\mathrm{.}8.$ What is the defect rate of the system in its present state