Answer:
upper control limit = 13.34
Step-by-step explanation:
The c-chart is used to check the change in the number of recorded calls per day
First find out the center line
c = sum of recorded calls/number of days
c = (3 + 0 + 8 + 9 + 6 + 7 + 4 + 9 + 8)/9
c = 54/9
c = 6
The upper control limit for 3σ is
upper control limit = c + 3√c
upper control limit = 6 + 3√6
upper control limit = 13.34
Therefore, the upper control limit for the 3-sigma c-chart is 13.34.
