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, $n=1094$ and $x=564$ who said "yes." Use a $90 \%$ confidence level. a) Find the best point estimate of the population proportion $p$.

Step 1 ：Given that the number of respondents who said 'yes' is $x = 564$ and the total number of respondents is $n = 1094$.

Step 2 ：The best point estimate of the population proportion $p$ is given by the formula $p = \frac{x}{n}$.

Step 3 ：Substitute $x = 564$ and $n = 1094$ into the formula to get $p = \frac{564}{1094}$.

Step 4 ：Simplify the fraction to get $p = 0.5155393053016454$.

Step 5 ：Round the result to four decimal places to get $p = 0.5155$.

Step 6 ：\(\boxed{0.5155}\) is the best point estimate of the population proportion $p$.