How many work cycles should be timed to estimate the average cycle time to within 4 percent of the sample mean with a confidence of 90.0 percent if a pilot study yielded these times (minutes): 4.1,4.6,5.1, 4.9, 5.9, and 4.4? The standard deviation is .631 minutes per cycle. (Use the "mean time" value to 2 decimal places and other values to 3 decimal places for intermediate calculations. Round up your final answer to the next whole number.)
Number of work cycles: