S statshelp New member Joined Apr 1, 2008 Messages 14 Apr 9, 2008 #1 If you know the length of a confidence interval for a proportion, How would you find the margin of error? Please Help!

If you know the length of a confidence interval for a proportion, How would you find the margin of error? Please Help!

R royhaas Full Member Joined Dec 14, 2005 Messages 832 Apr 9, 2008 #2 Re: confidence interval question How do you calculate the length of a confidence interval?

S statshelp New member Joined Apr 1, 2008 Messages 14 Apr 9, 2008 #3 Re: confidence interval question Max confidence interval - Min confidence interval / 2

R royhaas Full Member Joined Dec 14, 2005 Messages 832 Apr 9, 2008 #4 Re: confidence interval question No, the length is just the difference between the two endpoints of the interval. Now use the formulas for those endpoints and subtract them.

Re: confidence interval question No, the length is just the difference between the two endpoints of the interval. Now use the formulas for those endpoints and subtract them.

S statshelp New member Joined Apr 1, 2008 Messages 14 Apr 9, 2008 #5 Re: confidence interval question Ok so once I find the length, I then divide by 2, to find the margin of error?

Re: confidence interval question Ok so once I find the length, I then divide by 2, to find the margin of error?

R royhaas Full Member Joined Dec 14, 2005 Messages 832 Apr 9, 2008 #6 Re: confidence interval question Just like the calculation implies.