Refer to

Table S6.1 - Factors for Computing Control Chart Limits (3 sigma) SampleSize, nMean Factor,

ASubscript2

Upper Range,

DSubscript4

Lower Range,

DSubscript3

21.8803.268031.0232.574040.7292.282050.5772.115060.4832.004070.4191.9240.07680.3731.8640.13690.3371.8160.184100.3081.7770.223120.2661.7160.284

for this problem.Twelve samples, each containing five parts, were taken from a process that produces steel rods at Emmanual Kodzi's factory. The length of each rod in the samples was determined. The results were tabulated and sample means and ranges were computed. The results were:

Sample	Sample Mean (in.)	Range (in.)	Sample	Sample Mean (in.)	Range (in.)
1	11.70411.704	0.0220.022	7	11.70111.701	0.0210.021
2	11.70011.700	0.0320.032	8	11.70311.703	0.0200.020
3	11.69311.693	0.0170.017	9	11.69311.693	0.0140.014
4	11.70611.706	0.0410.041	10	11.70111.701	0.0150.015
5	11.69911.699	0.0230.023	11	11.70111.701	0.0220.022
6	11.69711.697	0.0210.021	12	11.70611.706	0.0320.032

Part 2For the given data, the

x double overbarx

=

enter your response here

inches (round your response to four decimal places).