63% of internet users are careful about personal information on public Wi-Fi according to a poll. The probability that at least one of three randomly selected internet users is careful is 0.981. This result assumes the survey subjects voluntarily responded to the poll.

1. Based on a poll, 63% of Internet users are more careful about personal information when using a
public Wi-Fi hotspot. What is the probability that among three randomly selected Internet users,
at least one is more careful about personal information when using a public Wi-Fi hotspot? How
is the result affected by the additional information that the survey subjects volunteered to
respond? The probability that at least one of them is careful about personal information is 0.981 .
(Round to three decimal places as needed.)