BUS140HW5 - to give me the sample size figures for the next...

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Professor Denzler BUS140 29 October 2008 Control Chart Memo The first thing we had to figure out was the range and the mean of the four samples from each of the first 20 runs. Once we obtained that we could figure out what the R-bar is, which can be calculated by taking the sum of all the ranges and dividing it by the number of runs, in this case 20. (sum(range)/20). Then we must calculate x-barbar by taking the sum of all the sample means and dividing by the number of runs, or 20. (sum(mean)/20). Once we’ve obtained these two figures we could calculate the Upper Control Limit (UCL) and the Lower Control Limit (LCL). We calculate the UCL by adding the x-bar bar to the given A2 times the R-bar (x-bar bar + (A2xR-bar)). Then we calculate the LCL by subtracting the x-bar bar minus the given A2 times the R-bar (x-bar bar + (A2xR-bar)). For this example the last number of my SSN was one so I pushed the F9 button one time
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Unformatted text preview: to give me the sample size figures for the next 20 outcomes. Once I obtained those numbers I copy/pasted them onto the second worksheet along with the x-bar bar, UCL and LCL from worksheet one. Now I needed to figure out the sample mean for each run by adding up the four sample sizes and dividing them by four. Once this was complete we could construct a control chart from the data we have calculated. In the control chart you could see the sample mean being depicted by the blue line, the x-barbar being depicted by the pink line, the UCL line being depicted by the yellow line and the LCL being depicted by the light blue line. From this chart we can observe that no sample mean exceeded the UCL or went below the LCL. This tells us that our operations are under control and we should continue running operations as they are....
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