In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster. UFO Poll In a Kelton Research poll, 1114 Americans 18 years of age or...

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

UFO Poll In a Kelton Research poll, 1114 Americans 18 years of age or older were called after their telephone numbers were randomly generated by a computer, and 36% of the respondents said that they believe in the existence of UFOs.