Problem 6. The time needed for checking in at a hotel is to be investigated. Historically, the process has had a standard deviation equal to .146. The means of 39 samples of n = 14 are Sample Mean Sample Mean Sample Mean Sample Mean 11 21 1 2 12 22 23 3 13 4 3.86 3.90 3.83 3.81 3.84 3.83 3.87 14 24 3.88 3.86 3.88 3.81 3.83 3.86 3.82 3.86 5 15 25 3.84 3.82 3.89 3.86 3.88 3.90 3.81 3.86 3.98 3.96 31 32 33 34 35 36 37 38 39 3.88 3.76 3.83 3.77 3.86 3.80 3.84 3.79 3.85 26 6 7 16 17 27 8 18 28 3.88 3.84 3.80 9 10 19 3.84 3.87 29 30 20 a. Construct an X-chart for this process with three-sigma limits. Is the process in control? Draw the mean chart using excel (preferred) or by hand while determining if the process is in control