Answer:
(0.1886,0.5724)
Explanation:
Given that in a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to 2457 subjects randomly selected from an online group involved with ears. 935 surveys were returned.
Sample proportion of returned surveys =

Sample size n =2457
q =

Std error of proportion =

a) the best point estimate of the population proportion p.=0.3805
b) Margin of error = 1.96* std error =

c) Confidence interval =
