An automatic filling machine is used to fill 1-liter bottles of cola. The machine's output is normal with a mean of 1 liter and a standard deviation of 0.02 liters. The output is monitored using means of samples of 25 observations. Compute the 3-sigma control limits. Using the following sample means, determine if the process is stable or not.
1.007, 1.002, 0.994, 1.010, 0.997, 0.998