Final answer:
The probability that at least one user is careful with personal information on public Wi-Fi is 1.000 for a large sample size, but volunteer bias may affect the accuracy of the result. The selection of volunteers, as opposed to a random sample, can affect the reliability and validity of the survey. Choice A is the most appropriate response, as it recognizes the potential problem with the sample not being representative because it was self-selected.
Step-by-step explanation:
The question asks about the probability that among randomly selected Internet users, at least one is more careful about personal information when using a public Wi-Fi hotspot, given that 61% of users are more careful. To find this probability, we need to use the complement rule which states that the probability of at least one event occurring is equal to 1 minus the probability of none occurring.
The probability that an individual is not careful is 39% (100% - 61%). If we randomly select one Internet user, the probability that they are not careful is 0.39. For n Internet users selected, this probability would be 0.39^n. To find the probability that at least one is careful, we subtract this value from 1. Assuming that 'n' tends towards a large number, the probability that at least one person is careful approaches 1 very quickly (since 0.39 to a large power approaches 0). The result could be affected by the fact that subjects volunteered to respond, which may introduce bias into the sample. This could lead to an overestimate or underestimate of the true proportion of careful users. The selection of volunteers, as opposed to a random sample, can affect the reliability and validity of the survey. Choice A is the most appropriate response, as it recognizes the potential problem with the sample not being representative because it was self-selected.