please answer correctly. if stuck between answers put both answers, I can check work.

The time in minutes to replace vehicle wiper blades at a service center was monitored using a mean and a range chart. Six samples of n=20 observations were obtained and the sample means and ranges were computed: Click here for the Excel Data File Factors for three-sigma control limits for x and R charts a. Using the factors in the above table, determine upper and lower limits for mean and range charts. (Do not round intermediate calculations. Round your mean value to 3 decimal places and range value to 4 decimal places.) a1. Is the process in control? The process is in control. b. The time in minutes needed to assemble security cameras at a production facility was recorded for eight samples of 15 observations each, and means and ranges were computed. Using factors from the above table, compute control limits for the means and ranges. (Round your answers to 3 decimal places.) b1. Is the process is in control. The process is in control. The process is not in control. \begin{tabular}{|c|c|c|c|c|c|} \hline Sample & Mean & Range & Sample & Mean & Range \\ \hline 1 & 3.06 & 0.42 & 4.00 & 3.13 & 0.46 \\ \hline 2 & 3.15 & 0.50 & 5.00 & 3.06 & 0.46 \\ \hline 3 & 3.11 & 0.41 & 6.00 & 3.09 & 0.45 \\ \hline \end{tabular}