CPM Homework Help : INT3 Problem 12-102

Every hour, Miguel’s Microchips measures the signal strength of a chip from their manufacturing process. For each of the process control charts below, say whether the process is in control, and if not, what in the manufacturing process could have led to the out-of-control state.

Line graph, with 5 horizontal lines, creating 4 spaces. Points are connected from left to right in these spaces as follows: 2, 3, 2, 2, 3, 2, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 1. Note: within each space, there is variability in the points' heights.

Line graph, with 5 horizontal lines, creating 4 spaces. Points are connected from left to right in these spaces as follows: 4, 1, 3, 2, 3, 4, 1, 3, 2, 4, 2, 2, 3, 2, 3, 3, 2, 1, 1, 4. Note: within each space, there is variability in the points' heights.

Line graph, with 5 horizontal lines, creating 4 spaces. Points are connected from left to right in these spaces as follows: 2, 2, 3, 2, 3, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3. Note: within each space, there is variability in the points' heights.

Answer:

The process is out of control beginning at the $9$ th hour.
There are $12$ consecutive points above the center line.