Answer:
20 miles with a margin of error of 8 miles
Explanation:
Given a data ''A'' and its margin of error ''B'', we can state that the value ''A'' will fall in the interval :
[A-B,A+B]
For example, is the value of the parameter ''X'' is 10 and its margin of error is 5, this means that the parameter X can assume any value in the interval
[10-5,10+5] ⇒ [5,15]
For example : 6 , 11 and 14.34 are possible values for X.
In the exercise, the parameter is the average distance commuters in the metro Atlanta area have to drive everyday to work.
The correct option for this exercise is
20 miles with a margin of error of 8 miles because we can define the following interval :
[20-8,20+8] ⇒ [12,28]
This means, that the parameter is between 12 and 28 miles