Question

From a phone survey, a researcher determined that the true estimate for the proportion of voters who will reelect the mayor is likely to be in the interval (0.39, 0.47) .
What is the survey’s margin of error?

Answer 1

Here, p^ = (0.39 + 0.47)/2 = 0.43

The given interval is (0.43 - 0.04, 0.43 + 0.04).

Therefore, the margin of error is 0.04.