How sensitive are the untrained noses of students? You want to estimate the mean DMS odor threshold among all students and you would be satisfied to estimate the mean to within ±0.1 with90% confidence. The standard deviation of the odor threshold for untrained noses is known to be confidence. The standard deviation of the odor threshold for untrained noses is known to be confidence. The standard deviation of the odor threshold for untrained noses is known to be =8 micrograms per liter of wine. How large an SRS of untrained students do you need?