Among 420 randomly selected employees at a company, the mean number of hours of overtime worked per month is 10 hours and the standard deviation is 1.6. What is the margin of error, assuming a 99% confidence level? 4.12 0.01 0.20 20.5 A 4-column table has 2 rows. The first column has entries Confidence level (percentage), z-score. The second column has entries 90, 1.645. The third column has entries 96, 1.96. The fourth column has entries 99, 2.58.