Advances in technology are dramatically affecting different aspects of our lives. For example, the number of daily print newspapers is decreasing because of easy access to Internet and television news. To help address such issues, we want to estimate the percentage of adults in the United States who use a computer at least once each day. Find the sample size needed to estimate that percentage. Assume that we want 95% confidence that the sample percentage is within two percentage points of the true population percentage.

The values are departure delay times (minutes) for American Airlines flights from New York to Los Angeles. Negative values correspond to flights that departed early.