Problem 3. NP charts. Using the following formulas:

np = number of defective pieces per sample

Where k is the number of measurements

)

)

Np charts are used instead of P charts when the sample size is constant.

For the following Process, what is the control chart look like if a constant sample of 200 was used for 20 measurements? np (defects in 20 measurements, 200 constant sample size each):

Rejects

2

5

4

0

1

6

4

3

5

7

8

4

5

6

4

5

3

5

0

3