Marlow wants to know how many students in his school enjoy watching the tv news. he asks all 27 students in his art class and finds that 30% of his classmates enjoy watching the tv news. he claims that 30% of the school's student population would be expected to enjoy watching the tv news. is marlow making a valid inference about his population?

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no, it is not a valid inference because he asked all 27 students in his art class instead of taking a sample from the school

no, it is not a valid inference because his classmates do not make up a random sample of the students in the school

yes, it is a valid inference because he asked all 27 students in his art class

yes, it is a valid inference because his classmates make up a random sample of the students in the school