10:02 Search Done Switch To Light Mode b. Identify the value of the margin of error E. c. Construct the confidence interval. 3. Find the sample size needed to estimate the percentage of adults who can wiggle their ears. Use a margin of error of 3 percentage points and use a confidence level of 99%. 4. Find the sample size needed to estimate the percentage of adults who can wiggle their ears. Use a margin of error of 3 percentage points and use a confidence level of 99%. a. Assume are unknown. b. Assume that 22% of adults can wiggle their ears.