A nationwide poll claims that the margin of error is no more than 3 percentage points in either direction (i.e., plus or minus) at the 95% confidence level.
a. Verify this claim in a particular case by computing the t table value times the standard error of the binomial fraction p for the case of 309 out of 1,105 registered voters reporting that they are in favor of a particular candidate.
b. Find the 95% confidence interval for the percentage of registered voters who favor the candidate as indicated in part a.