Please look at the data given by the question, it is different from the previous ones, and don't use it incorrectly. And explain how A2, D3 and D4 came to be

Task 4: Ten samples of 80 kg concrete slabs produced by a machine are collected. Each sample has three observations provided in the following table): Sample: 1 2 3 5 6 7 8 9 79.2 80.5 79.6 78.9 80.5 79.7 79.6 78.9 80.5 78.9 10 78.8 78.7 79.4 79.4 79.6 80.6 79.6 80.9 78.9 78.7 Observations 79.9 80.9 80.3 79.6 80.3 80.4 80.4 78.7 80.9 80.5 a. If the weight specification limits for a slab are 79kg (LSL) and 81kg (USL), what is the Cpk? Is the production process capable? Why (not)? [4 Marks) b. Using A2, D3 and D4 factors, determine the upper and lower control limits for sample mean and range, and decide if the process is in control. State the reason for your decision. [6 Marks] (Please use Excel for accurate results. Round final answers to 4 decimal places.)