Question

Kim wants to know how many families in her small neighborhood of 70 homes would participate in a neighborhood sports event. She put all the addresses in a bag and drew a random sample of 35 addresses. She then asked those families if they would participate in the sports event. She found that 15% of the families would participate in the event. She claims that 15% of the neighborhood families would be expected to participate in the sports event. Is this a valid inference?
Yes, this is a valid inference because she took a random sample of the neighborhood Yes, this is a valid inference because the 35 families speak for the whole neighborhood No, this is not a valid inference because she asked only 35 families No, this is not a valid inference because she did not take a random sample of the neighborhood