Managers at an automobile manufacturing plant would like to estimate the mean completion time of an assembly line operations, u. The managers plan to choose a random sample of completion times and estimate u via the sample. Assuming that the standard deviation of the population of completion times is 10.4 minutes, what is the minimum sample size needed for the managers to be 95% confident that their estimate is within 1.7 minutes of u?

Carry your intermediate computations to at least 3 decimal places.

Write your answer as a whole number.