At a certain plant, batteries are being produced with a life expectancy that has a variance of 5,76 months squared. Suppose the mean life expectancy is an SRS of 64 batteries is 12,35 months. 1) Find a 90% confidence interval estimate of life expectancy for all batteries produced at this plant. 2) What would the 90% confidence interval estimate be if the sample mean of 12,35 had come from a sample of 100 batteries?