Question

A machine fills boxes with cereal. The labeled weight is 9 oz. The quality control department sampled three boxes every day for five days.

The samples are as follows:

Sample	Box Weights (oz)
1	9.41	8.82	8.88	8.66
2	9.08	8.61	8.86	9.33
3	8.9	9.45	8.6	8.75

What is the upper control limit (UCL) of R chart (refer to the table below if necessary)? (Keep two decimal points.)

		Factor for R Chart
Number of Observations in Subgroup	Factor for x-bar Chart	Lower Control Limit	Upper Control Limit
n	A2	D3	D4
2	1.88	0.00	3.27
3	1.02	0.00	2.57
4	0.73	0.00	2.28

Answer 1

= 8.95

= 0.77

upper control limit UCL

For sample size n = 3

D₄ = 2.57

UCL_R = 2.57*0.77 = 1.99