Question

In a study of cell phone use and brain hemispheric​ dominance, an Internet survey was​ e-mailed to 2381 subjects randomly selected from an online group involved with ears.1144 surveys were returned. Construct a 95​% confidence interval for the proportion of returned surveys.

c) Construct the confidence interval.

____< p <____

​(Round to three decimal places as​ needed.)

Answer 1

We have given,              
              
x=1144          
n=2381          
Estimate for sample proportion=   0.4805  
Level of significance is =1-0.95=0.05      
Z critical value(using Z table)=1.96      
              
Confidence interval formula is              


=(0.460,0.501)

0.460 < p < 0.501