Each year, Lord & Taylor, Ltd., sets up a gift-wrapping station to assist its customers with holiday shopping. Preliminary observations of one worker at the station produced the following sample time (in minutes per package): 3.5, 3.2, 4.1, 3.6, 3.9. Based on this small sample, what number of observations would be necessary to determine the true cycle time with a 95% confidence level and an accuracy of 5%?