Determine upper and lower control limits-need to help with part b. and need to know if part a. is ...

An automatic filling machine is used to fill 1-liter bottles of cola. The machine’s output is approximately normal with a mean of 0.94 liter and a standard deviation of 0.04 liter. Output is monitored using means of samples of 28 observations.

a. Determine upper and lower control limits that will include roughly 97 percent of the sample means when the process is in control. (Do not round intermediate calculations. Round z value to 2 decimal places. Round your answers to 4 decimal places.)

Are my answers correct?
Upper control limits:  .9564 liter 
 Lower control limits: .9236 liter

b. Given these sample means: 1.005, 1.001, .998, 1.002, .995, and .999, is the process in control? Yes or No? Can you explain why the answer is yes or no?