A newspaper report conducted a survey of 609 people in the Bay Area and found that 39% of the population believe that a large earthquake will hit San Francisco by the end of the year. In the accompanying dialogue, the report states, we are 95% confident that the true proportion of people in the Bay Area who believe that a large earthquake will hit San Francisco by the end of the year lies between 31% and 47% . What does 8% represent in the report?
A.
a margin of error
B.
a parameter
C.
a statistic
D.
a confidence interval
E.
a confidence level