A First Course in Quality Engineering, 2nd Edition

124 A First Course in Quality Engineering

Set 1 Set 2

0 0

1

H H

H H

: :

: :

µ µ

µ µ

≤ ≥

> <

10 10

10 10

1

For both sets, the test statistic is:

X

n

Z

−10

σ

∼ .

The supplier’s claim is included in H

1

in Set 1, whereas the claim is included

in H

0

in Set 2 (with the implied > sign as part of H

0

). The CR corresponding to

each set is shown in Figure 2�21�

In order to understand the difference between the two sets, let us focus on

the event that the supplier’s claim is accepted when it is not true, which is

an important event from the point of view of a customer and should be con-

trolled� In Set 1, this event happens when H

0

is rejected when it is true� This is

the ...