TRUE/FALSE
1.Some degree of variability is present in almost all processes.
2.The purpose of process control is to detect when natural causes of variation are present.
3.A normal distribution is generally described by its two parameters: the mean and the range.
4.A process is said to be in statistical control when assignable causes are the only sources of variation.
5.Mistakes stemming from workers' inadequate training represent an assignable cause of variation.
6.Averages of small samples, not individual measurements, are generally used in statistical process control.
7.The X-bar chart indicates that a gain or loss of uniformity has occurred in dispersion of a production process.
8.The Central Limit Theorem states that when the sample size increases, the distribution of the sample means will approach the normal distribution.
9.In statistical process control, the range often substitutes for the standard deviation.
10.If the process average is in control, then the process range must also be in control.
11.A process range chart illustrates the amount of variation within the samples.
12.Mean charts and range charts complement one another, one detecting shifts in process average, the other detecting shifts in process dispersion.
13.X-bar charts are used when we are sampling attributes.
14.To measure the voltage of batteries, one would sample by attributes.
15.A p-chart is appropriate to plot the number of typographic errors per page of text.