Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:1800:p12
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 1800 (pt 12/12)
Character Range: 534139–535815

shall be tested on the basis of a 10 per cent significance level of the F and t values. The critical F and t values for seven to ten sample pairs are given in Table 9. If the F and t values calculated according to the equation below are greater than the critical F and t values, the candidate system is not equivalent.
 The following procedure shall be followed. The subscripts R and C refer to the reference and candidate system, respectively:
(a) Conduct at least seven tests with the candidate and reference systems operated in parallel. The number of tests is referred to as nR and nC;
(b) Calculate the mean values  and  and the standard deviations sR and sC;
(c) Calculate the F value, as follows:
 (108)
                  (the greater of the two standard deviations sR or sC shall be in the numerator);
(d) Calculate the t value, as follows:
 (109)
(e) Compare the calculated F and t values with the critical F and t values corresponding to the respective number of tests indicated in Table 9. If larger sample sizes are selected, consult statistical tables for 10 per cent significance (90 per cent confidence) level;
(f) Determine the degrees of freedom (df), as follows:
For the F-test: df1 = nR –1, df2 = nC –1 (110)
For the t-test: df = (nC + nR –2)/2 (111)
(g) Determine the equivalency, as follows:
(i) If F < Fcrit and t < tcrit, then the candidate system is equivalent to the reference system of this annex;
(ii) If F  Fcrit or t  tcrit , then the candidate system is different from the reference system of this annex.
       Table 9
       t and F values for selected sample sizes
Sample Size  F-test         t-test
             df      Fcrit  df      tcrit