Refer to Example 6.3 (page 293) to find the standard deviation of the delay departures for Delta Airlines is given by σ=25.83.
Use the sample size formula (page 311) to determine what sample size you need to have a margin of error equal to two minutes with 90% confidence. Explain why you must always round up to the next higher whole number when using the formula for n.
What sample size do you need to have a margin of error equal to two minutes with 95% confidence?