OMB Meeting Book_9-11-14

Table 15: Bias results for NIST 1849a CRM practice sample

Sample ID: Sample 1 L-2794/F-3353

CMP

UMP

GMP

IMP

AMP

Analyte

Seq.

Item

Symbol

Value

Value

Value

Value

Value

1 2

Mean

28.1 26.8

11.8 12.9

15.1 14.6

0.0 n/a

10.9 10.5

µ

Certified value

U CRV

3

Uncertainty

2.90

1.50

1.10

n/a

0.53

k

4

Coverage factor

2.57

2.57

2.57

n/a

2.57

5

Nominal bias

S R

+5.0%

-8.9%

+3.2%

n/a

+3.5%

6

Students test-statistic

t Stat DF

1.16

1.92

1.05

n/a

1.63

7

Degrees of freedom

5.6

5.4

6.1

n/a

7.3

8

p-value

0.30

0.11

0.34

n/a

0.15