Using samples of 197 credit card statements, an auditor found the following: Sample 1   3 errors Sample 2   3 errors Sample 3   5 errors Sample 4    9 errors 1. what alpha risk would control limits of .0470 and .0038 provide? 2. Using control limits of .0470 and .0038, is the process in control? 3. Construct a control chart for the process, assuming a fraction defective of 2 percent, using two-sigma control limits.  Is the process in control?

Twenty samples of 100 items each were inspected when a process was considered to be operating satisfactorily. In the 20 samples, a total of 140 items were found to be defective. (a) What is an estimate of the proportion defective when the process is in control? (b) What is the standard error of the proportion if samples of size 100 will be used for statistical process control? (Round your answer to four decimal places.) (c) Compute the upper and lower control limits for the control chart. (Round your answers to four decimal places.) UCL = LCL =

A shirt manufacturer buys clothes by the 100-yard roll from a supplier. For setting a control chart to manage the irregularities (e.g., loose threads and tears), the following data were collected from a sample provided by the supplier.   Sample 1 2 3 4 5 6 7 8 9 10 Irregularities 3 5 2 6 5 4 6 3 4 5   Which type of control chart should be used? Construct a control chart with two-sigma control limits. Suppose the next five rolls from the supplier had three, two, five, three, and seven irregularities. Is the supplier process under control? Explain and show work

Hermitage DNA Labs, LLC collected temperature readings in an analysis process. The data can be found in the Problems Data Compute the mean and range of each sample and calculate control limits for x-bar and R charts using the appropriate From the charts constructed, does the process appear to be in statistical control?

Refer to Table 56.1-Factors for Computing Control Chart Limits.(3.sigma) for this problem. Auto pistons at Wemming Chung's plant in Shanghai are produced in a forging process, and the diameter is a critical factor that must be controlled. From sample sizes of 10 pistons produced each day, the mean and the range of this diameter have been as follows: a) What is the value of x? mm (round your response to two decimal places). b) What is the value of R? R=mm (round your response to two decimal places). c) What are the UCL, and LCL; using 3-sigma? Day 1 2 3 4 5 Upper Control Limit (UCL;)mm (round your response to two decimal places) Lower Control Limit (LCL;)mm (round your response to two decimal places). d) What are the UCL and LCL using 3-sigma? Upper Control Limit (UCLR)-mm (round your response to two decimal places). Lower Control Limit (LCL)-mm (round your response to two decimal places) Mean x (mm) 154.9 151.2 155.6 155.5 154.6 Range R (mm) 4.4 4.8 4.3 5.0 4.7 Next

Freshly painted tables are inspected for blemishes in samples of size 1. The results for inspecting 12 samples follow:  Sample # Blemishes 1 4 2 12 3 7 4 10 5 8 6 12 7 2 8 14 9 4 10 11 11 6 12 15 Total blemishes: 105 Total tables inspected = 12*1 = 12 What is the value of the statistic plotted for sample 3?  Same table data. What is the Lower Control Limit for the most appropriate control chart?  Same table data. What is the lower boundary value between Zone B and Zone C? That is, what is the boundary between the Zones B and C that lie below the process average?

Suppose that a quality characteristic is normally distributed with specifications at 100 ± 20. The process standard deviation is 6.(a) Suppose that the process mean is 100. What are the natural tolerance limits? Calculate Cp and Cpk and interpret these ratios. What fraction of parts do you expect to be defective?(b) Suppose that the process mean is 106. What are the natural tolerance limits? What is thefraction defective? Calculate Cp and Cpk and interpret these ratios.

54 Boxes of Honey-Nut Oatmeal are produced to contain 14.0 ounces, with a standard deviation of 0.20 ounce. For a sample size of 64, the 3-sigma X chart control limits are: Upper Control Limit (UCL) = ounces (round your response to two decimal places).

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A control chart for fraction nonconforming is to be established using a center line of p=0.03. What sample size is required if we wish to detect a shift in the process fraction nonconforming to 0.08 with probability 0.50? 1269 475 73 316 216 2 105 150 265