A candidate for the Senate creates an automated message that calls every third listed phone number and reminds them to vote for him in the upcoming election
Indentify what type of sampling is used.

Marquise has 200 meters of fencing to build a rectangular garden. the garden's area (in square meters) as a function of the garden's width w w (in meters) is modeled by: a ( w ) = − w 2 + 1 0 0 w a(w)=−w 2 +100w what side width will produce the maximum garden area? meters