1. What is a cause-and-effect diagram?
A. A diagram that organizes the logical relationships between the inputs and stages of a process and an output.
B. A picture of the stages of a process.
C. A scatterplot that uses different plotting symbols for points that correspond to different possible causes.
D. A bar chart of problems where the bars are ordered by the frequency of problems.
2. The number of customers at a specialty meat store averages about 1500/day. The exact number varies from day to day. On Fridays before long weekends, the number of customers increases to about 3000. Which of the following statements is correct?
A. The variation in number of customers on a typical day is an example of common cause variation.
B. The increase in the number of customers before long weekends is an example of common cause variation.
C. The variation in the number of customers on a typical day is an example of special cause variation.
D. The increase in the number of customers before long weekends is variation that is due neither to common causes nor to special causes, but is just an outlier.
3. Bags of chips are filled using a machine. Because not all chips are the same size, it is impossible to get the exact target weight in each bag. The target weight is 75 g. Based on samples of size 4, the average standard deviation is about 0.5 g and the average weight of the last batch of four bags was 74 g. Which of the following are the upper and lower control limits for an control chart?
A. (74.25, 74.75) mm.
B. (73.5, 76.5) mm.
C. (74.25, 75.75) mm.
D. (72.5, 75.5) mm.