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Table 1 Iteration-based improvement in minimum number of nematode samples needed to achieve a 10% level of reliability as defined in terms of standard error to mean ratio (E) or confidence interval half-width to mean ratio (D) with iteration*

From: Plant-parasitic nematodes of strawberry in Egypt: a review

Mean count per sample+ Number of samples via (E) Student’s t value Number of samples via (D)++ Improvement in sample size
Pratylenchus spp.: The power law parameters a = 1.58, b = 1.33
 1 158 2 (assumed) 632 609 and 209 instead of 632 and 215 samples, respectively
1.964 (n = 632) 609
1.9638 (n = 609) 609
 5 54 2 (assumed) 215
1.971 (n = 215) 209
1.971 (n = 209) 209
Meloidogyne incognita: The power law parameters a = 2.92, b = 1.47
 5 124 2 (assumed) 498 480 and 375 instead of 498 and 388 samples, respectively
1.966 (n = 498) 480
1.965 (n = 480) 480
 8 97 2 (assumed) 388
1.966 (n = 388) 375
1.966 (n = 375) 375
  1. *The t value is either assumed as 2 for 95% confidence interval or iterated using its tabulated value from: http://www.danielsoper.com/statcalc3/calc.aspx?id=10
  2. +Based on a sample size of 100 g soil (iterated from original data reported by Abd-Elgawad et al. (2008))
  3. ++The fractional values rounded up to nearest integer