You have 30 boxes of the a1 ball bearings in your plant. you immediately had them weighed. the weights of the boxes are: 40.1 41.1 39.5 40.1 39.1 41.237.639.141.640.8 43.238.938.143.536.9 39.140.541.237.644.0 38.039.842.138.641.3 43.736.943.638.140.2 calculate the mean and the standard deviation of this sample.
