Replication Long-Run monthly cost (dollars) 1 412.11 2 437.60 3 411.26 4 455.75 (1) Suppose an inventory system simulation has 4 independent replications, the average long run monthly costs for each replication are shown in the above table. Use the above data to calculate long-run mean monthly cost with a 90% confidence interval. (2) If the outputs are normally distributed, what is the probability that the average long-run monthly cost is less than $420? (3) Say the simulation initially made Ro = 4 independent replications, the observed data is shown in the above table. If the error criterion is = $5 and confidence coefficient is 1-a = 0.90, find a sample size R that can meet this criterion