To assess consumer acceptance of a new series of ads for Miller Lite Beer, Louis Harris conducted a nationwide poll of 363 adults who had seen the Miller Lite ads (USA Today, November 17, 1997). The following responses are based on that survey. (Note: Because the survey sampled only a small fraction of all adults, assume (N - n)/N = 1 in any formulas involving the standard error.)

a. Nineteen percent of all respondents indicated they liked the ads a lot. Develop a 95% confidence interval for the population proportion.

b. Thirty-one percent of the respondents disliked the new ads. Develop a 95% confidence interval for the population proportion.

c. Seventeen percent of the respondents felt the ads are very effective. Develop a 95% confidence interval for the proportion of adults who think the ads are very effective.

d. Louis Harris reported that the "margin of error is five percentage points." What does this statement mean and how do you think they arrived at this number?

e. How might nonsampling error bias the results of such a survey?