# control chart

1. ### Defining "low-range" of a data set

Hi all! So here is the scenario, I have a linear non-weighted calibration curve. I run a bunch of tests and gather data from which I can derive a control chart. This gives me "acceptance criteria" for a passing test, from a statistical perspective. Let's say +-20% from a known value. But this...
2. ### P charts based on binomial distribution - Statistical Process Control

Hello all, I have a question related to the use of p-chart in a process where there are defect rates measured. The control limits for this type of chart is calculated with +/- 3 sigmas around the mean (with mean = np and sd = sqrt(n*(1-p)*p)) As it is using i +/- 3 sigmas it assumes that we...
3. ### Changing a target value that minimize the product being outside the specifications in

I was doing problems in the article here. http://elearning.vtu.ac.in/10/enotes/06IPIM65/Mod10-NVN.pdf In the question on page 16 I don't understand part b) how to find a target value that minimize the product being outside the specifications. Can someone please explain to...
4. ### Changing process average in control charts

Data is given for a X bar and R chart of subgroup size=4. . The control limits are for X bar chart: center line=178.46 UCL=184.1146 LCL=172.8054 for R chart: center line=8.3888 UCL=17.734 LCL=0 In this question I don't understand to do the following part : . Can...
5. ### WineGlass model anyone?

Hi..i have been asked to prepare a wineglass control chart which is used by retail chains for supply chain management. I googled, but there is hardly any information out there. Please help.
6. ### Xbart Chart-Missing Data(correct sum) Question

Good Morning, I'm in a business statistics course and I understand how to make a xbar and rchart in excel when all the data is available to me, but I just can't seem to figure out the problem below. Any help would be much appreciated! Thank you!! Here's the question: Using the data...
7. ### Contro Chart Sub-group size

My first post. Is there a formula for subgroup size for average control charts for variables.