Physics Excel Worksheet

The hardest part about this assignment is finding the center line. The center line is always X-bar-bar. (An x with two bars above it). It's the mean of all the sample means.
I've attached an Excel spreadsheet showing how to calculate X-bar-bar. First, you find the average of each sampe. There were four in this case. The average is at the bottom. Then you take those four numbers and find the average for those. I rounded up to 5.1 to make it easier to graph. So X-bar-bar = 5.1. Once you X-bar-bar then, it all comes together.
For the first part, the center line (CL) is 5.100 and the CLR = 1.083. Then use the formula for the control limits: ± A2 = 5.100 ± 0.729 (1.083) = 4.31 to 5.89 For the R-chart: UCLR = D4 = 2.282 (1.083) = 2.47
LCLR = D3
X-bar Chart
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Sample number
Averages
Averages
Lower control limit
Upper control limit
Center line

3. We can see from the above - chart that points 19 and 21 are out of control and the R-chart shows point 18 is out of control on the range. We obtain the following control limits and related charts after dropping these 3 points:

4a. New Center Lines: Center Lines, CL : = 5.037; CLR : = 1.057 Control limits for the - chart are:

± A2 = 5.037 ± 0.729 (1.057) = 4.266 to 5.808

For the R-chart: UCLR = D4 = 2.282 (1.057) = 2.412 LCLR = D3 = 0

4b.

New X-bar Chart
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