The 47th Annual PDK/Gallup Poll of the Public's Attitudes toward the Public Schools, conducted in May 2015, sampled 4,500 adult Americans and found that 64% feel there is too much emphasis on standardized testing in the public schools in their community. Using the quick method, the estimated margin of error for conclusions having 95% confidence about the entire adult population of adult Americans is %. (Give your answer to one decimal place.)