T

**MSA r.3 Bias Analysis**

p. 86, the new numerical analysis of results, calculation 7)

I'm stuck. Can't calc the (tv,1-significance level/2).

Using the data in the example, I get this far:

Trials Reading Bias Reference value = 6.00

1 5.8 -0.2

2 5.7 -0.3

3 5.9 -0.1

4 5.9 -0.1

5 6.0 0.0

6 6.1 0.1

7 6.0 0.0

8 6.1 0.1

9 6.4 0.4

10 6.3 0.3

11 6.0 0.0

12 6.1 0.1

13 6.2 0.2

14 5.6 -0.4

15 6.0 0.0

6.0067 average reading

0.8 Range o f readings

0.0067 average error (bias); rounded to 4 decimals

3.55333 g=1, m=15, d*2=3.55333, Appendix C d2 table 0.225140924 std dev of range = R/d*2

15 n

3.872983346 sqrt n

0.05813 uncert. of bias is std dev of range/sqrt of n, rounded to 5 decimals

0.1153 t=bias/uncertainty for bias, rounded to 4 decimals

10.8 v=degrees of freedom, Appendix C d*2 table

3.47193 d2= infinity value of d*2, Appendix C d*2 table

0.112658697 (d2 x uncert of bias)/d*2)

0.975 1-signif level/2 from formula p.86 (tv,1-signif level/2); 1-(0.05/2) = 1-0.025 = 0.975

(tv,1-signif level/2) t = 0.1153, v = 10.8 ???????????

????? 95% Confidence Interval of the Bias, Lower ((d2 x uncert of bias)/d*2) x (tv,1-signif level/2)

What's wrong with me that I can't understand simple statistics ?

TommyT.