For a fixed confidence level, show that (approximately) quadrupling the sample size is necessary to halve the margin of error.

(Hint: Use Formula 8.2.)

Another type of confidence interval is called a one-sided confidence interval. A one-sided confidence interval provides either a lower confidence bound or an upper confidence bound for the parameter in question. You are asked to examine one-sided confidence intervals in Exercises 8.105–8.107.