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, $n=1031$ and $x=552$ who said "yes." Use a $95 \%$ confidence level. Click the icon to view a table of $z$ scores. a) Find the best point estimate of the population proportion $p$. 0.535 (Round to three decimal places as needed.) b) Identify the value of the margin of error $E$. \[ E= \] (Round to three decimal places as needed.)

Step 1 ：Given that the total number of respondents, n = 1031, and the number of 'yes' responses, x = 552, we can calculate the best point estimate of the population proportion p as the ratio of 'yes' responses to the total responses. This gives us \(p = \frac{x}{n} = \frac{552}{1031} = 0.535\).

Step 2 ：The margin of error E for a proportion is calculated using the formula \(E = z \sqrt{\frac{p(1-p)}{n}}\), where z is the z-score corresponding to the desired confidence level. For a 95% confidence level, the z-score is approximately 1.96.

Step 3 ：Substituting the given values into the formula, we get \(E = 1.96 \sqrt{\frac{0.535(1-0.535)}{1031}} = 0.030\).

Step 4 ：Thus, the best point estimate of the population proportion p is approximately 0.535 and the margin of error E is approximately 0.030.

Step 5 ：So, the final answers are \(p = \boxed{0.535}\) and \(E = \boxed{0.030}\).