We have taken 12 samples of 400 letters each from a typing pool and found the following proportions of defective letters:.01, .02, .02, .00, .01, .03, .02, .01, .00, .04, .03, .02

A letter is considered defective when one or more errors are detected.

Calculate the control limits for a p control chart. Show your work somewhere. You can use any designation for a square root sign.

Complete a control chart, plotting your CL, UCL, LCL and 12 sample defect amounts. Feel free to use the Excel template provided for you. Once you compute your CL, UCL and LCL, the template will guide you through how to create the chart.

Is this process in control? Why or why not?

An additional sample of 400 letters has just been taken, and 6 letters were found to be defective. With this new data, is the process in control? Why or why not? You need to compute the percentage of defects in this sample (6/400).