level given below to complete parts (a) through (d). 90% confidence level. A research institute poll asked respondents if they felt vulnerable to identity theft. In the poll, n = 1027 and x = 557 who said "yes." Use a a ) Find the best point estimate of the population proportion po b) Identify the value of the margin of error E . () Construct the confidence interval. d ) write a statement that correctly interprets the cofidence interval