Question

Question 4 (1 point) What % of the healthy population is excluded from a reference interval established by +/- 2SD of the mean? a) 95% b) 5% c) 66% d) 2.5% e) 97.5%

Answer 1

Ans) d) 2.5%

Explaination:

- An absolute minimum of 40 samples is required to compute a reference interval that includes 95 % from the mid range of a data set and excludes 2.5

- With the parametric approach, the central 95% boundaries are specified by the mean ± 2SD, if the data follow a Gaussian (normal) distribution or can be transformed to a normal distribution by one of several two-step transformation methods 21 and with the non-parametric approach, the central 95% boundaries are determined by trimming off the lowest and highest 2.5% of observations. % at either end of the range.