Table 3.

Summary of mean % relative errors according to PE concentration ranges (training set).

PE Concentration (w/w%)	No of Samples	Mean %RE	Min–Max %RE
<1	12	6.57	1.22–12.07
[1, 2]	10	5.21	0.55–9.86
[2, 3]	10	1.77	0.91–3.74
[3, 4]	8	2.44	0.95–6.43
[4, 5]	6	2.63	0.49–5.73
[5, 6]	4	5.13	3.46–7.31
[6, 7]	6	1.52	0.19–4.76
[7, 8]	4	2.35	1.54–3.14
>8	4	1.52	1.02–2.28