In: Statistics and Probability
Given that,
In a sample of 500 people, 325 indicated they would vote in the next presidential election. Now we want to construct a 95% confidence interval estimate for the proportion of people who will vote in the next presidential election.
Calculation:-
Sample proportion:-

Calculation of significance level:-



Critical Values:-
[ Value are getting from Z-table ]
Margin of error:-

Now we put the value of 
, 
, 
 and we get,
  


[Round to four decimal places]
95% Confidence Interval:-



Answer:- 95% confidence interval estimate for the proportion of people who will vote in the next presidential election is 0.6082 to 0.6918