X bar should never be interpreted when:

Related MCQs

• Consider the first method of p bar estimation where each sample is of varying size. If the 3rd sample has p bar =.01, and the sample size of the 3rd sample is 10, what will be the upper control limit for the 3rd sample?
• When data is plotted on the control charts, the data is of two types: R and -bar. The R data represent points of a ______________ while the X-bar data represent points of a (n) ______________.
• If we want to detect small process shifts using x bar chart, we should use a sample size of:
• For the above table, what is the value corresponding to the central line for the x bar chart?
• The x bar chart monitors:
• For an x bar chart, β risk can be defined as:
• Consider that for a process s bar (average standard deviation of 50 samples each of size 4) is found to be 10.04. The value of c4 (corresponding to sample size of .4) is .92. What is the estimated value of process standard deviation?
• X bar charts are uses to control the ______________ of a process.
• Given that for the three samples, the value of R bar is .66 and value of d2 corresponding to three is1.128, what is the estimated standard deviation?
• Assume the cholesterol levels in a certain population have mean μ = 200 and standard deviation σ = 24. The cholesterol levels for a random sample of n = 9 individuals are measured and the sample mean x-bar is determined. What is the z-score for a sample mean x = 180?