Please help with computing the critical value for the 97% confidence level. It’s the key piece for computing the UCL and LCL but I’m totally not understanding how to get it.
An automatic filling machine is used to fill 1-liter bottles of cola. The machine’s output is approximately normal with a mean of .90 liter and a standard deviation of .03 liter. Output is monitored using means of samples of 28 observations. Use Table-A.
a.Determine upper and lower control limits that will include roughly 97 percent of the sample means when the process is in control.