Question 1
The causes of variation in statistical process control are
◦ Type I and Type II.
◦ cycles, trends, seasonality, and random variations.
◦ producer's causes and consumer's causes.
◦ mean and range.
◦ natural causes and assignable causes.
Question 2
Natural variations
◦ affect almost every production process.
◦ when grouped, form a pattern, or distribution.
◦ are the many sources of variation that occur when a process is under control.
◦ are tolerated, within limits, when a process is under control.
◦ All of the above are true.