In: Statistics and Probability
Use the sample data and confidence level given below to complete parts (a) through (d). A research institute poll asked respondents if they felt vulnerable to identity theft. In the poll, n = 1049 and x = 510 who said "yes." Use a 95% confidence level.
a) Find the best point estimate of the population proportion p.
Solution :
Given that,
a)
Point estimate = sample proportion = 
 = x / n = 510 / 1049 = 0.486
1 - 
 = 1 - 0.486 = 0.514
Z
/2
= 1.96
Margin of error = E = Z
/ 2 * 
((
* (1 - 
)) / n)
= 1.96 * (((0.486
* 0.514) / 1049)
Margin of error = E = 0.030
A 95% confidence interval for population proportion p is ,
- E < p < 
 + E
0.486 - 0.030 < p < 0.486 + 0.030
0.456 < p < 0.516
The 95% confidence interval for the population proportion p is : 0.456 , 0.516