What is the upper control limit (UCL) for a c-chart (using a 3 sigma control limit) if a total of 180 defects were found over 20 samples?

a) 3

b) 9

c) 18

d) 20

e) 7.5

With a products life cycle, phases of maturity and decline are also referred to as:

		a) the early stages
		b) the adjustment stages
		c) the later stages or end stages
		d) design for manufacture stages
		e) re-engineering stages

A company is looking to better understand the output of a process by developing appropriate SPC charts. The company is looking to develop an R-bar chart for the process using 3 sigma control limits (z=3). For the following dataset (Table 1), calculate the Center Line (R-bar) for the process control chart.

Table 1

	Sample 1	Sample 2	Sample 3	Sample 4
Observation 1	15.802	15.901	15.543	15.527
Observation 2	15.874	15.746	15.634	15.545
Observation 3	15.601	15.564	15.857	15.458
Observation 4	15.545	15.862	15.873	15.892
Observation 5	15.787	15.376	15.354	15.867

The dataset is composed of 4 samples (k=4) with 5 observations in each sample (n=5). Calculation to 5 decimal places (5dp). Note your answer for questions 21 and 22.

		a) 0.84631
		b) 0.37254
		c) 0.45175
		d) 0
		e) 0.68574

1 points

QUESTION 21

For the R-bar chart developed in Question 20. What is the Upper Control Limit (UCL) for the process control chart?

Calculation to 5 decimal places (5dp)

		a) 0.95319
		b) 0
		c) 1
		d) 0.58183
		e) 0.82856

1 points

QUESTION 22

For the R-bar chart developed in Question 20. What is the Lower Control Limit (UCL) for the process control chart? Calculation to 5 decimal places (5dp)

		a) 0.0356
		b) 0.01452
		c) 1
		d) 0
		e) 0.08423