In: Statistics and Probability
In a survey of 1000 people, 700 said that they voted in a recent presidential election. Voting records show that 61% of eligible voters actually did vote. Construct a 96% confidence interval estimate of the proportion of people who say that voted.
We have given,          
   
          
   
x=700          
n=1000          
Estimate for sample proportion=0.7  
Level of significance is =1-0.96=0.04  
   
Z critical value(using Z table)=2.054  
   
          
   
Confidence interval formula is      
       
=(0.6702, 0.7298)