Assume that a sample is used to estimate a population proportion p. Find the 80% confidence interval for a sample of size 398 with 223 successes. Enter your answer as an open-interval (i.e., parentheses) using decimals (not percents) accurate to three decimal places. 80% C.I. = Answer should be obtained without any preliminary rounding. However, the critical value may be rounded to 3 decimal places.