Answer:
the margin of error for this interval is 0.049
Explanation:
The computation of the margin of error for this interval is shown below;
Given that
n = 400
x = 200
Now
p = x ÷ n = 200 ÷ 400 = 0.5
Now the margin of error is
=

= 0.049
Hence the margin of error for this interval is 0.049