470

1. The Speedway Clinical Laboratory is a scientific blood-testing facility that receivessamples from local hospitals and clinics. The blood samples are passed through severalautomated tests, and the results are printed through a central computer that readsand stores the information about each sample that is tested.

Management is concerned about the quality of the service it provides and wants toestablish quality-control limits as a measure for the quality of its tests. Such managerialpractice is viewed as significant, because incorrect analysis of a sample can leadto a wrong diagnosis by the physician, which in turn might cost the life of a patient.

For this reason, 100 blood samples were collected at random each day after they hadgone through testing. After retesting was performed manually on this sample, theresults were:

Day

Incorrect Analysis

Day

Incorrect Analysis

Day

Incorrect Analysis

1

8

8

6

15

2

2

3

9

3

16

1

3

1

10

1

17

0

4

0

11

4

18

6

5

4

12

6

19

3

6

2

13

5

20

2

7

9

14

10