E-mail. A small company involved in e-commerce is interested in statistics concerning the use of e-mail. A poll found that 38% of a random sample of 1012 adults, who use a computer at their home, work, or school, said that they do not send or receive e-mail.

a) Find the margin of error for this poll if we want 90% confidence in our estimate of the percent of American adults who do not use e-mail.

b) Explain what that margin of error means.

c) If we want to be 99% confident, will the margin of error be larger or smaller? Explain.

d) Find that margin of error.

e) In general, if all other aspects of the situation remain the same, will smaller margins of error involve greater or less confidence in the interval?