In 2014, news reports worldwide alleged that the U.S. government had hacked German chancellor Angela Merkel’s cell phone. A Pew Research Center survey of German citizens at about that time asked whether they find it acceptable or unacceptable for the U.S. government to monitor communications from their country’s leaders. Results from the survey show that of 1000 citizens interviewed, 900 found it unacceptable. (Source: Pew Research Center, July 2014, “Global Opposition to U.S. Surveillance and Drones, But Limited Harm to America’s Image”)

a. Find the point estimate of the population proportion of German citizens who find spying unacceptable.
b. The Pew Research Center reports a margin of error at the 95% confidence level of 4.5% for this survey. Explain what this means.