Answer:
In simple words, Representative surveys are valuable because they mean that the questionnaire contains all different categories of individuals and also that the correct blend of individuals is questioned. Your results will be skewed if your study isn't representative. The poll's inconsistency was due to an unbalanced, non-representative sample.
Answer:
Contributions to schools and Public safety and
justice
Explanation:
Testimonials, illustrations and explanations are all supporting materials. So the answer is all of the above.