To test whether the mean time needed to mix a batch of material is the same for machines produced by three manufacturers, the Jacobs Chemical Company obtained the following data on the time (in minutes) needed to mix the material. Manufacturer 1 2 3 22 32 17 28 30 16 26 35 20 24 31 19 a. Use these data to test whether the population mean times for mixing a batch of material differ for the three manufacturers. Use a = 0.05. Compute the values below (to 2 decimals, if necessary). Sum of Squares, Treatment Sum of Squares, Error