Question

Mark wants to know how many families in his neighborhood plan to attend the neighborhood party. He puts all 80 of the neighborhood addresses in a hat and draws a random sample of 20 addresses. He then asks those families if they plan to attend the party. He finds that 20% of the families plan to attend the party. He claims that 20% of the neighborhood families would be expected to attend the party. Is this a valid inference?

A. No, this is not a valid inference because he asked only 20 families
B. No, this is not a valid inference because he did not take a random sample of the neighborhood
C. Yes, this is a valid inference because he took a random sample of the neighborhood
D. Yes, this is a valid inference because the 20 families speak for the whole neighborhood

Answer 1

A. No, this is not a valid inference because he asked only 20 families

Explanation:

You cannot assume that those are the only families that would want to go; you have to ask all the families.