A researcher studying a new treatment to increase the lung capacity (liters of air you can breathe out in one second) for patients with COPD randomly assigns 50 patients to the new treatment and 50 to a placebo. The lung capacity is measured for all subjects at baseline before any treatment and then again three days later. In the placebo group the measurements averaged 0.04 liters higher than baseline with a standard deviation of 0.26 liters while for the treatment group they averaged 0.16 liters higher than baseline with a standard deviation of 0.28 liters. The standard error (in liters) for the difference in the averages for the two groups (treatment group - placebo group) is then