An​ assembly-line machine turns out washers with the following thicknesses​ (in millimeters). Find the mean and standard deviation of the thicknesses.
1.42, 1.83, 1.43, 1.87, 1.22, 1.44, 1.72, 1.91, 1.42, 1.87, 1.42, 1.99, 1.27, 1.94, 1.67, 1.22