How do i find the margin of error that correspons to a 94% confidence level.

Question

I having probles with understanding how to find the margin of error an d

 

Answer 1

From http://stattrek.com/estimation/margin-of-error.aspx :

 

The margin of error can be defined by either of the following equations.

Margin of error = Critical value x Standard deviation of the statistic, or
Margin of error = Critical value x Standard error of the statistic

If you know the standard deviation of the statistic, use the first equation to compute the margin of error. Otherwise, use the second equation.

 

Critical value for a 94% confidence level (2-sided) is 1.880793608151249 rounded off to 1.881. So,

 

Margin of error = 1.881 x Standard deviation of the statistic, or

Margin of error = 1.881 x Standard error of the statistic