Chapter 21: I-MR Charts

When n=2, an estimate of the standard error of the mean when determining the UCL in an I-MR chart is computed by dividing the average range by ___________.

1.128

An I-MR chart only monitors the range of a process since the means of samples is not relevant when the sample size is one.

FALSE

If one observation is 10 and the next is 12, the range plotted in an I-MR chart would be 12.

FALSE

In an I-MR chart, the sample must be greater than two.

FALSE

The "I" in the I-MR chart represents the "Interval" of two successive observations.

FALSE

The "MR" in an I-MR Chart represents the "maximum ratio" which is used an approximation for sample variation.

FALSE

The centerline in an I-MR chart that monitors means is determined by taking several preliminary samples, determining the range for those samples and then computing the average for all of those ranges.

FALSE

Which control chart should be used when the subgroup size is 1.

I-MR

After an I-MR chart has been designed, it is used to plot the range associated with the current sample which is calculated by subtracting the current outcome from the previous outcome and then using the absolute value of this result.

TRUE

An I-MR chart is not used for monitoring proportions.

TRUE

Assume the sample size is 2. The UCL in an I-MR chart that monitors individual observations is plus 3 standard errors of the mean from the process mean where the estimate of the standard error of the mean is the average MR divided by 1.128.

TRUE

The I-MR chart is unusual in that the results of individual samples (samples of size 1) are plotted on a chart not sample means.

TRUE

When computing the range in an I-MR Chart, the absolute value of successive observations is used.

TRUE