Given:
[tex]\begin{gathered} n=1086 \\ x=571 \end{gathered}[/tex]
To Determine: Using 99% confidence interval, the best point of estimate of the population of portion p
Solution
[tex]\begin{gathered} Point-of-estimation(PE)=\frac{x}{n} \\ PE=\frac{571}{1086} \\ PE=0.5258 \end{gathered}[/tex]
The formula for finding the margin of error is
[tex]MOE=\sqrt{\frac{0.5258\times(1-0.5258)}{1086}}\times z[/tex][tex]\begin{gathered} MOE=\sqrt{\frac{0.24933436}{1086}}\times z \\ MOE=0.01515\times z \end{gathered}[/tex]
The z score corresponding to 99% confidence interval from the table is 2.575
Therefore
[tex]\begin{gathered} MOE=0.01515\times2.575 \\ MOE=0.039 \end{gathered}[/tex]
Hence
A. Point of estimation of the population of portion p is approximately 0.5258 (4 decimal places) OR 0.526(3 decimal places)
B. The margin of Error is apprimately 0.039