Question

From the following data, calculate the control limits for the mean and range chart.

Sample No.	1	2	3	4	5	6	7	8	9	10
Sample Observations	50	51	50	48	46	55	45	50	47	56
	55	50	53	53	50	51	48	56	53	53
	52	53	48	50	44	56	53	54	49	55
	49	50	52	51	48	47	48	53	52	54
	54	46	47	53	47	51	51	57	54	52

Answer 1

Since the sample size is 5, we used A₂ = 0.577, D₃ = 0, D₄ = 2.114, from the table given.

We see that one sample \(\overline{X}\) value 47 is below the LCL of \(\overline{X}\) . To infer that the process is not totally out of control since^the difference is less. Further investigation is recommended.