Answer:
-1.25
Step-by-step explanation:
The lower control limit for the 3 sigma c chart is :
cbar - 3√cbar
central line = cbar = Σc / n
n = size
Given the data :
3, 0, 8, 9, 6, 7, 9, 8
Σc = 50
n = 8
cbar = 50/8
cbar = 6.25
Lower Control Limit = cbar - 3√cbar
Lower Control Limit = 6.25 - 3√6.25
Lower control limit = 6.25 - 7.5
Lower control limit = -1.25