Please help me solve this

QUESTION 4 A quality inspector took five samples, each with four observations, of the length of time (in minutes) for glue to dry. The analyst computed the mean of each sample as 11.97, 10.95, 11.76, 11.28, and 11.76. Use this information and alpha risk of 0.04 to obtain control limits for means of future times. It is known from previous experience that the standard deviation of the process is 1.35 minute. STEP 1: Provide control limits for the mean chart: LCL = CL = UCL= STEP 2: The inspector continued to periodically sample the process and recorded values for six samples as shown in the following table. SAMPLE Observation 1 2 3 4 5 6 1 12.84 13.32 12.36 10.44 13.32 9.96 2 12.24 13.68 12.24 12.96 12.60 13.68 3 12.48 12.72 11.04 11.76 11.76 12.96 4 10.80 14.40 14.40 10.80 12.00 12.60 Enter the values you plot in mean chart, starting from the first sample: Sample 1: Sample 2: Sample 3: Sample 4: Sample 5: Sample 6: Is the process in control (Enter YES or NO): NOTE: All computed values should be rounded to the nearest hundredth (two decimal after dot, for example 9.99)