Task 2: Ten samples of 80 kg concrete slabs produced by a machine are collected. Each sample has four observations (provided in the following table):

Sample:	1	2	3	4	5	6	7	8	9	10
Observations	79.2	80.5	79.6	78.9	80.5	79.7	79.6	78.7	79.4	79.4
	78.8	78.7	79.6	79.4	79.6	80.6	79.6	79.6	80.3	80.4
	80.9	78.9	80.9	79.4	79.6	80.6	79.6	80.5	79.6	79.4
	79.9	80.9	80.3	79.6	80.3	80.4	80.4	78.9	80.5	79.7

Standard deviation of the 40 observations is 0.6432

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]

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]

(You can use Excel for accurate results. Show the calculations for Cpk and upper and lower control limits.)