In a study done by the Society of Human Resources Management, a random sample of 341 human resource professionals were asked, “On average, how many paid vacation days does your organization offer to employees who have been with the organization for 10 years or more?” The average response was 18.65 days. The margin of error was reported as one day, at the 95% confidence level.
a. Show the upper and lower bounds for the 95% confidence interval.
b. What would the margin of error be for a 90% confidence level?