A Quality Analyst Wants to Construct a Control Chart for Determining

Multiple Choice

A quality analyst wants to construct a control chart for determining whether three machines, all producing the same product, are in control with regard to a particular quality variable. Accordingly, he sampled four units of output from each machine, with the following results

For upper and lower control limits of 23.29 and 16.71, which machine(s) , if any, appear(s) to have an out-of-control process mean?

A) machine #1
B) machine #2
C) machine #3
D) all of the machines
E) none of the machines