Item2 Item 2 6.66 points
Time Remaining 1 hour 23 minutes 43 seconds
01:23:43
Problem 10-4
Computer upgrades have a nominal time of 80 minutes. Samples of five observations each have been taken, and the results are as listed.
SAMPLE
1 2 3 4 5 6
79.2 80.5 79.6 78.9 80.5 79.7
78.8 78.7 79.6 79.4 79.6 80.6
80.0 81.0 80.4 79.7 80.4 80.5
78.4 80.4 80.3 79.4 80.8 80.0
81.0 80.1 80.8 80.6 78.8 81.1
Factors for three-sigma control limits for x¯x¯ and R charts
FACTORS FOR R CHARTS
Number of Observations in Subgroup,
n Factor for
x¯x¯ Chart,
A2 Lower
Control Limit,
D3 Upper
Control Limit,
D4
2 1.88 0 3.27
3 1.02 0 2.57
4 0.73 0 2.28
5 0.58 0 2.11
6 0.48 0 2.00
7 0.42 0.08 1.92
8 0.37 0.14 1.86
9 0.34 0.18 1.82
10 0.31 0.22 1.78
11 0.29 0.26 1.74
12 0.27 0.28 1.72
13 0.25 0.31 1.69
14 0.24 0.33 1.67
15 0.22 0.35 1.65
16 0.21 0.36 1.64
17 0.20 0.38 1.62
18 0.19 0.39 1.61
19 0.19 0.40 1.60
20 0.18 0.41 1.59

a. Using factors from above table, determine upper and lower control limits for mean and range charts. (Round your intermediate calculations and final answers to 2 decimal places. Leave no cells blank - be certain to enter "0" wherever required.)
Mean Chart Range Chart
UCL
LCL