Managers at an automobile manufacturing plant would like to estimate the mean completion time of an assembly line operation, J. The managers plan to choose a random sample of completion times and estimate ( via the sample. Assuming that the standard deviation of the population of completion times is 1 minutes, what is the minimum sample size needed for the managers to be 95% confident that their estimate is within 1.7 minutes of ? Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements). (If necessary, consult a list of formulas.) X