Question: A two-standard-deviation interval is called the margin of sampling error (or the margin of error or the sampling error) by most pollsters.
a. In repeated sampling, how often will the distance between a sample proportion and the true proportion be less than the margin of error?
b. Using the class dot plots constructed earlier in this lesson, count the number of times a sample proportion is less than two standard deviations from the true proportion for each plot. Do the results agree with your answer to part a?