A Gallup poll of 547 adult Americans employed full or part time asked, "Generally speaking, would you say your commute to work is-very stressful, somewhat stressful, not that stressful, or not stressful at all?" Gallup reported that 24% of American workers said that their commute was "very" or "somewhat" stressful. The margin of error was 4 percentage points with 95% confidence. Explain what this means.