When the author observed a sobriety checkpoint conducted by the Dutchess County Sheriff Department, he saw that 676 drivers were screened and 6 were arrested for dri vi ng while intoxicated. Based on those​ results, we can estimate that P(I) = 0.00589​, where W denotes the event of screening a driver and getting someone who is intoxicated. What does P(I¯) ​denote, and what is its​ value?