In: Statistics and Probability
In a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to
2592
subjects randomly selected from an online group involved with ears.
913
surveys were returned. Construct a
99%
confidence interval for the proportion of returned surveys.
We have given,
x=913
n=2592
Estimate for sample proportion=
0.3522
Level of significance is =1-0.99=0.01
Z critical value(using Z table)=2.576
Confidence interval formula is
=(0.3280,0.3764 )
Lower limit for confidence interval=0.328
Upper limit for confidence interval=0.3764