A vaccine manufacturer analyzes a batch of product to check its titer. Immunologic analyses are imperfect, and repeated measurements on the same batch are expected to yield slightly different titers. Assume titer measurements vary according to a normal distribution with mean µ and σ = 0.070. Three measurements demonstrate titers of 7.40, 7.36 and 7.45. Calculate a 95% confidence interval for true concentration of the sample.

;A vaccine manufacturer analyzes a batch of product to check its titer. Immunologic analyses are imperfect, and repeated measurements on the same batch are expected to yield slightly different titers. Assume titer measurements vary according to a normal distribution with mean µ and σ = 0.070. Three measurements demonstrate titers of 7.40, 7.36 and 7.45. Calculate a 95% confidence interval for true concentration of the sample.