Question

A survey of factories in five northeastern states found that 10% of the 300 workers surveyed were satisfied with the benefits offered by their employers. The margin of error for the population proportion is ____.

Answer 1

Margin of error for a population proportion is given by = p^ + or - sqrt(p^(1 - p^)/n); where p^ = 10% = 0.1 and n = 300

margin of error = 0.1 + or - sqrt(0.1(1 - 0.1)/300) = 0.1 + or - sqrt(0.09/300) = 0.1 + or - 0.017 = 0.083 to 0.117 = 8.3% to 11.7% = 25 to 35 workers