LSSGB: Which of the following charts have upper control limits, but frequently have lower control limits of zero?
OPTIONS
- X-bar and individual charts
- c charts and u charts
- p charts and np charts
- R and sigma charts
ANSWER
R and sigma charts
EXPLANATION
X-bar and individual charts, u charts, p charts, and np charts have lower control limits. In case of some of the attribute charts, the calculated value is negative, which will be shown as zero. R and sigma charts are the charts that have an upper control limit, but may often have a lower control limit of zero.
