Q1 X and R chart

A quality engineer collected process data for 10 subgroups with each subgroup consisting of four samples (n=4). The averages and ranges of samples in each subgroup are summarized in Table 1 below.

Table 1. Subgroup Data

Subgroup	1	2	3	4	5	6	7	8	9	10
Average X	13.01	12.99	13.01	12.99	12.98	12.93	12.93	13.00	13.01	13.01
Range R	0.06	0.04	0.03	0.05	0.04	0.06	0.07	0.03	0.04	0.06

(1-7) Create R chart with center line, UCL, and LCL, and plot subgroup data in the below figure. Clearly label center line, UCL, and LCL.

(1-8) Answer questions in the below table on this process based on subgroup ranges in R chart.

		Answer
Is this process in control in terms of subgroup ranges?	Yes or No
Briefly explain reason of your above answer	Explain
Do you suspect that there are variations due to common causes?	Yes or No
Briefly explain reason of your above answer	Explain
Do you suspect that there are variations due to assignable causes?	Yes or No
Briefly explain reason of your above answer	Explain

ate R chart with center line, UCL, and LCL, and plot subgroup data in the below figure. Clearly ter line, UCL, and LCL. wer questions in the below table on this process based on subgroup ranges in R chart