Paula wants to know what movie people are going to see at her favorite local theater Friday night.  If she surveys every fifth woman that buys a ticket at the box office, this sample is  random . If she surveys every third person that enters theater four, this sample is  . If she surveys every fourth person that walks by the concession stand, this sample is  . If she surveys every sixth child in the arcade, this sample is  . If she surveys every fifth person that goes through the exit, this sample is