Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:5:p36
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 5 (pt 36/36)
Character Range: 520487–521876

basis of a 5 % significance level of the F and t values. The critical F and t values for 7 to 10 sample pairs are given in the table below. If the F and t values calculated according to the formulae 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 7 tests with the candidate and reference systems preferably operated in parallel. The number of tests is referred to as nR and nC.

       (b)     Calculate the mean values xR and xC and the standard deviations sR and sC.

       (c)     Calculate the F value, as follows:

   (the greater of the two standard deviations SR or SC must be in the numerator)

       (d)    Calculate the t value, as follows:

       (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 below. If larger sample sizes are selected, consult statistical tables for 5 % significance (95 % confidence) level.

       (f)      Determine the degrees of freedom (df), as follows:

   for the F-test:  df = nR – 1 / nC – 1
   for the t-test:  df = nC + nR – 2

F and t values for selected sample sizes

Sample Size  F-test  t-test
             df      Fcrit   df  tcrit