A restaurant is improving its processes, and is currently focusing on the final bill presented to customers. The manager samples 50 bills per day for 12 days, and checks to see how many are incorrect using a z-value of 3.

[ Select ] ["Special cause is evident since day 6 is above UCL", "No special cause is evident", "Special cause is evident since 5 different days are above and 7 are below average complaint rates", "Special cause is evident since the Upper Control Limit is above the z-value of 3"] Is the billing process consistent (in other words, is it in control), or do special cause events appear to be present?

[ Select ] [".1456%", ".1456 incorrect bills", "14.56%", "14.56 incorrect bills"] What is the UCL?

[ Select ] ["3.13%", "There is no LCL since there is always at least 1 incorrect bill in the sample", "0%", "5.17%"] What is the LCL?

Day	Day 1	Day 2	Day 3	Day 4	Day 5	Day 6	Day 7	Day 8	Day 9	Day 10	Day 11	Day 12
Bills Sampled	50	50	50	50	50	50	50	50	50	50	50	50
Incorrect Bills	1	3	2	1	4	8	2	1	1	3	1	4

You collect two more days of data, again sampling 50 bills per day, and add the results (11 incorrect bills on day 13, and 9 on day 14) to the control chart.

3 How many days are now outside the control limits?

18.31% What is the UCL?

[ Select ] ["5.17%", "0%", "7.58%", "There is no LCL since there is always at least 1 incorrect bill in the sample"] What is the LCL?