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

Machine Measurements

Number1 17 15 15 17

Number2 16 25 18 25

Number3 23 24 23 22

What is the estimate of the process mean for whenever it is under control?

a) 16

b) 19

c) 20

d) 21

e) 23

2. Specifications for a piece of material used in the manufacture of a bed mattress require that the piece be between 82.05 and 83.95 inches. The process that produces the piece yields a mean of 83 and a standard deviation of 0.5 inches. The distribution of output is normal. What percentage of the pieces will meet the length specs?

a) 72.86%

b) 2.87%

c) 97.12%

d) 94.25%

e) none of these