Confidence Int. Ans.

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1. Approximately 95%.
   
2. The 99% confidence interval is wider and less precise because of the required shift in the value of z_conf (from +/- 1.96 for 95% to +/- 2.58 for 99%.)
   
3. Except for chance, sample size has no affect on the percent of true confidence intervals; sample size affects only the size of the standard error and, therefore, the width of the confidence interval.
   
4. Larger sample sizes culminate in more precise, narrower confidence intervals.