Problem 1 . We have taken 11 samples of 96 bulbs each from a manufacturing line and found the following proportions of defectives: .04, .06, .03, .02, .05, .03, .02, .04, .04, .05, and .06. Calculate the control limits for a p control chart.
Problem 2. In a control chart application, we have found that the grand average over all past samples of size 6 is = 30 and = 6.
a. Setup and R control charts for this application.
b. The following measurements are taken: 38, 35, 25, 34, 33, and 35. Is the process still in control?
Problem . A Hardware store has sold the following number of mowers for the past three days. Assuming a = 0.1, complete the following table. You must provide details of calculations for each entry filled in the table to earn credit.
Period | Dt | Ft | et | MADt | Tracking Signal |
0 | 20 | ||||
1 | 300 | 290 | |||
2 | 280 | ||||
3 | 309 |