Question $21(1$ point$)$

Plots of sample ranges indicate that the most recent value is below the lower control limit$.$ What course of action would you recommend?

Question $21$ options:

a$)$

Lower than expected dispersion is a desirable condition; there is no reason to investigate.

b$)$

One value outside the control limits is insufficient to warrant any action.

c$)$

Variation is not in control; investigate what created this condition.

d$)$

Since there is no obvious pattern in the measurements, variability is in control.

e$)$

The process is out of control; reject the last units produced.