Question 1

Which of the following of these situations is most likely to reflect only common cause variation?

Group of answer choices

A fast food restaurant near an office park monitors the time from order input to completion and plots the daily average. Over time, it appears that the weekend averages are lower than the week day averages.

An inspector measures a part several times in a row with the same device but the measurements vary slightly

Data is collected on the error rate in completing forms. Several new employees are hired and the error rate increases, then decreases, over the month

All of the above.