Answer:
the survey population is very isolated
Step-by-step explanation:
There is not much information to go on but from the information provided we can say that the biggest problem is that the survey population is very isolated. Bob gave the survey to every single individual in his block, this does not represent the entire population of the people that use the community pool. Therefore, the data would not represent the entire population. Instead, Bob should have randomly chosen mailboxes from the entire community to give them the survey.