Looking for Margin of Error

Question

Suppose you calculate a 99% confidence interval of 14.95 to 20.26. Determine the margin of error. Please explain the steps one would take in figuring this out. Thanks!

Answer 1

Hi Char,

The margin of error tells you the range of values above and below the confidence interval.

Mean+ margin of error= upper CI -> X+Y= upper CI

Mean- margin or error= lower CI -> X- Y= lower CI

(solving using systems of equations):

2X= upper CI +lower CI

X=35.21/2 = 17.605

(substitution):

17.605+ margin or error= 20.26

MOE= 2.66

I hope this helps! Feel free to reach out to me if you need a more detailed explanation of this concept.

Best,

Amy