Part 4 - What if we found that the sample statistic and the corresponding margin of error based on the ENTIRE American Community Survey(ACS) sample turned out to be a sample proportion is 0.155 with a margin of error of 0.0001 (for 90% confidence level) again for the entire sample.(important we stay with the results written here).

Q: Why is the margin of error so different from the either of the ones you computed in part (3)?[ Why is it different from those margin of errorsfrom part 1 and part 2 confidence intervals?]