Descriptions of three nationwide poll results follow.

Each of the polls is based on approximately 1020 randomly selected adults.

a. Calculate the 95% confidence maximum error of estimate for the true binomial proportion based on binomial experiments with the same sample size and observed proportion as listed first in each article.

b. Explain what caused the values of the maximum errors to vary.

c. The margin of error being reported is typically the value of the maximum error rounded to the next larger whole percentage. Do your results in part a verify this?

d. Explain why the round-up practice is considered “conservative”?

e. What value of p should be used to calculate the standard error if the most conservative margin of error is desired?

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CNN/USA Today/Gallup Poll, June 21-23, 2002; N 1020 adults nationwide; MoE+ 3. (MoE is margin of error.) "Do you think school districts should or should not be allowed to test public school students for illegal drugs before those students can participate in non-ath- letic activities?" Should be allowed-70%, Should not be allowed-29%, No opinion-1%