(a)
To determine: The sample means and ranges, and whether this process is in control by using table 10.3. and mean and range charts when the time to replace vehicle wiper blades at a service center was monitored where 6 samples of n = 20 observations were collected.
Introduction: To monitor the process dispersion, range control charts are used and the mean control limit charts are based on a
(b)
To determine: The sample means and ranges, and whether this process is in control by using table 10.3 according to the given table of b when the n is 15.
Introduction: To monitor the process dispersion, range control charts are used and the mean control limit charts are based on a normal distribution.
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EBK OPERATIONS MANAGEMENT
- Inter-State Moving and Storage Company wishes to establish a control chart to monitor the proportion of residential moves that result in written complaints due to late delivery, lost items, or damaged items. A sample of 40 moves is selected for each of the last 12 months. The number of written complaints in each sample is 9, 7, 4, 9, 1, 9, 11, 5, 5, 8, 7, and 15. Number Defective Percent defective 9 18 7 14 4 8 9 18 1 2 9 18 11 22 5 10 5 10 8 16 7 14 15 30 a. Insert the mean proportion defective, UCL, and LCL. (Leave no cells blank - be certain to enter "0" wherever required. Round your intermediate calculations and final answers to 2 decimal places.) Mean proportion defective UCL LCL c. Does it appear that the number of complaints is out of control for any of the months?multiple choice Yes Noarrow_forwardExplain how to contruct process control chart and use them to determine whether a process is out of statistical control.arrow_forwardAdministering new bank accounts is intended to average 15 minutes each. Five samples of four observations each have been taken. Use the sample data in concurrence with Table 2.3 to create upper and lower control limits for both a mean chart and a range chart. Do results propose that the procedure is in control? Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 11.2 11.3 10.7 10.9 10.8 10.9 10.8 10.9 11.3 11.2 10.8 10.9 10.9 11.1 11.3 11.1 11.4 11.1 11.5 10.7 Total: 44 44.4 43.6 44.8 44arrow_forward
- Chocolate, Inc. manufactures 4 ounce chocolate bars. Random samples of size four were taken and weighed. Eight hours of observation provided the following data. Sample Mean Range 1 3.96 0.13 2 4.03 0.16 3 3.97 0.16 4 4.14 0.16 5 3.88 0.11 6 4.03 0.18 7 4.04 0.18 8 4.07 0.14 (a) Determine the upper and lower control limits for the x chart. (Round your answers to four decimal places.) UCL=?? LCL=?? (b) Determine the upper and lower control limits for the R chart. (Round your answers to four decimal places.) UCL=?? LCL=??arrow_forwardThe time in minutes to replace vehicle wiper blades at a service center was monitored using a mean and a range chart. Six samples of n=20 observations were obtained nd the sample means and ranges were compared. Sample Mean Range 1 3.06 .42 2 3.15 .50 3 3.11 .41 4 3.13 .46 5 3.06 .46 6 3.09 .45 Using the factors in Table 10.3 in your text for 20 observations, determine the upper and lower limits for mean and range charts. Is the process within control limits?arrow_forwardWebster Chemical Company produces mastics and caulking for the construction industry. The product is blended in large mixers and then pumped into tubes and capped. Management is concerned about whether the filling process for tubes of caulking is in statistical control. The process should be centered on 8 ounces per tube. Several samples of eight tubes were taken, each tube was weighed, and the weights in Table were obtained. Ounces of Caulking Per Tube Tube Number Sample 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7.98 8.33 7.89 8.24 7.87 8.13 8.34 8.22 7.77 8.18 8.13 8.14 8.02 8.08 7.91 7.83 7.92 8.11 7.94 8.51 8.04 8.05 7.99 8.13 8.44 8.41 8.00 7.90 8.10 8.14 7.68 8.28 7.89 8.16 7.81 8.12 7.81 8.09 7.93 7.97 8.14 8.13 8.11 8.16 8.09 8.07 7.88 8.14 a. Assume that only six samples are sufficient and develop the control charts for the mean and the range.b. Plot the observations on the control chart and comment on your findings.arrow_forward
- When most processes are sampled for control chart purposes, why aren't they in statistical control?arrow_forwardDescribe how to construct process control charts and use them to determine whether a process is out of statistical control.arrow_forward13. A process is monitored using an X chart with UCL = 13.8 and LCL = 8.2. The process standard deviation is estimated to be 6.6. If the X chart is based on three-sigma limits, a. What is the estimate of the process mean? b. What is the size of each of the sampling subgroups?arrow_forward
- control charts for means and rangers. processing times for new accounts at bank are shown in the following table. five samples of four observations each have been taken. use the sample data in conjunction with table 10.3 to construct upper and lower control limits for both mean chart and range chart. do the result suggest that the process is in control? sample 1 sample 2 sample 3 sample 4 sample 5 10.2 10.3 9.7 9.9 9.8 9.9 9.8 9.9 10.3 10.2 9.8 9.9 9.9 10.1 10.3 10.1 10.4 10.1 10.5 9.7 40.0 40.4 39.6 40.8 40.0arrow_forwardWhat is the significance of the order of observation in process control?arrow_forwardIn process industry during a daily production run, a total of five (05) samples are collected with four (04) observations within each sample. The sample means (X-bar) are; 14.09, 13.94,16.86, 20.00, and 16.64 respectively. The corresponding ranges are; 9.90, 7.73, 4.41, 7.56, and 3.49 respectively. The lower and upper control limits of the x-bar chart are respectively O a. 11.44, 20.66 O b. 11.29, 20.65 C. None is correct Od. 11.47, 21.14 e. 11.47, 16.55arrow_forward
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