In a study of cell phone use and brain hemispheric dominance, an Internet survey was emailed to 2580 subjects randomly selected from an online group involved with ears. 1046 surveys were returned. Construct a 95% confidence interval for the proportion of returned surveys. @ Click the icon to view a table of z scores. a) Find the best point estimate of the population proportion p. (Round to three decimal places as needed.) b) Identify the value of the margin of error E. E = (Round to three decimal places as needed.) c) Construct the confidence interval.