Answer:
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 is 0.964
If the survey subjects <em>volunteered</em> to respond , then those with the strongest opinions are most likely respond. The survey sample is then not randomly selected, the survey may have a <em>response bias.</em>
Explanation:
Let P(at least one is more careful about personal information when using a public Wi-Fi hotspot) denote 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, then we have the equation
P(at least one is more careful about personal information when using a public Wi-Fi hotspot) = 1 - P(none of the selected users is more careful about personal information when using a public Wi-Fi hotspot)
- If 67% of Internet users are more careful about personal information when using a public Wi-Fi, then 33% of them are not.
P(none of the selected users is more careful about personal information when using a public Wi-Fi hotspot) = ≈ 0.036
P(at least one is more careful about personal information when using a public Wi-Fi hotspot) = 1 - 0.036 = 0.964