Problem: According to a census bureau,11.5% of the population in a certain country changed addresses from 2008 to 2009. In 2010,30 out of a random sample of 400 citizens of this country said they changed addresses during the previous year (in 2009). Complete parts a through c below. Provide justifications and citations for your responses.
Required:
a). A 98% confidence interval to estimate the actual proportion has a lower limit of ___ and an upper limit of ___.
b). What is the margin of error for this sample?