Question

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

Answer 1

The margin of error from a survey is half the witdth of the interval.

Margin of error = width of the interval / 2 = (0.47 - 0.39) / 2 = 0.08 / 2 = 0.04