Chapter 12, Problem 3E

(a)

To determine

To explain what kind of sample was this.

Answer to Problem 3E

It was a voluntary response.

Explanation of Solution

It is given in the question that the website asked their question of the day to which visitors to the site were invited to respond that do you ever use emoticons when you type online. Then, $27\%$ said that they did not use emoticons of the sample used. Thus, we can say that it was a voluntary response because they were voluntarily asked the question.

(b)

To determine

To find out how much confidence would you place in using $27\%$ as an estimate of the fraction of people who use emoticons.

Answer to Problem 3E

We do not have confidence.

Explanation of Solution

It is given in the question that the website asked their question of the day to which visitors to the site were invited to respond that do you ever use emoticons when you type online. Then, $27\%$ said that they did not use emoticons of the sample used. Thus, we have no confidence placed in using $27\%$ as an estimate of the fraction of people who use emoticons because this study was not proper and voluntary responses were given so it can be biased.