Progress Check Use this activity to assess whether you and your peers can:

Use a given margin of error to find and interpret the 95% confidence interval.
Context
A Gallup poll conducted in November of 2011 asked the following question, “What would you say is the most urgent health problem facing this country at the present time?” The choices were access, cost, obesity, cancer, government interference, or the flu. The responses were access (27%), cost (20%), obesity (14%), cancer (13%), government interference (3%), or the flu (less than 0.5%).

The following is an excerpt from the Survey Methods section. “Results for this Gallup poll are based on telephone interviews conducted Nov. 3-6, 2011, with a random sample of 1,012 adults ages 18 and older, living in all 50 U. S. states and the District of Columbia. For results based on a total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±4 percentage points.”

Prompt
If we accept the maximum margin of sampling error provided above, find a 95% confidence interval to estimate the percentage of U. S. adults who feel that access to healthcare is the most urgent health problem facing this country. Interpret your interval in context.