Jerome wants to know how many students in his school enjoy watching comedy programs on tv. he poses this question to all 28 students in his math class and finds that 70% of his classmates enjoy watching comedy programs on tv. he claims that 70% of the school's student population would be expected to enjoy watching comedy programs on tv. is jerome making a valid inference about this population?

Jerome's inference is invalid because his sampling technique is not random, and it may be biased.

Explanation:
A valid inference should survey a sufficiently large random sample from the school population.
A minimum sample size of 30 is recommended.
A class of math students may have habits, likes, and dislikes that are not representative of the school population.
A form of sampling such as simple or systematic sampling is more likely to yield credible inferences.