Question: A manager wants to investigate a bottling process by using a sample mean chart. He knows from his experience that the process standard deviation is
A manager wants to investigate a bottling process by using a sample mean chart. He knows from his experience that the process standard deviation is 4 mL (milliliter). Each day last week, he randomly selected 9 bottles and measured each. The data (in mL) from that activity appear below.
| Weight | |||||||||
| Day | Bottle 1 | Bottle 2 | Bottle 3 | Bottle 4 | Bottle 5 | Bottle 6 | Bottle 7 | Bottle 8 | Bottle 9 |
| Monday | 322 | 325 | 349 | 324 | 323 | 322 | 323 | 324 | 322 |
| Tuesday | 323 | 321 | 319 | 321 | 323 | 321 | 319 | 321 | 323 |
| Wednesday | 320 | 319 | 320 | 321 | 320 | 319 | 323 | 321 | 324 |
| Thursday | 318 | 319 | 320 | 319 | 318 | 319 | 320 | 319 | 328 |
| Friday | 318 | 320 | 322 | 320 | 318 | 327 | 322 | 320 | 320 |
- Calculate all the sample means and the mean of all the sample means.
- Calculate upper and lower x-bar chart control limits that allow for natural variations with a z value of 3.
- Based on the x-bar chart, is this process in control? Create a X-bar chart.
- Use the data to (a) create Range chart (b) Based on the R chart, is this process in control?
Step by Step Solution
There are 3 Steps involved in it
Get step-by-step solutions from verified subject matter experts
