The state education commission wants to estimate the fraction of tenth grade students that have reading skills at or below the eighth grade level. In an earlier study, the population proportion was estimated to be 0.23. How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 95 % confidence level with an error of at most 0.03? Round your answer up to the next integer.

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 = 992 and x = 581 who said "yes." Use a 99% confidence level. Click the icon to view a table of z scores. ..... a) Find the best point estimate of the population proportion p. (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.) c) Construct the confidence interval.