## The calculation of the 5% bit value and 95% bit value of the medium density fiberboard

GB/T 11718-202X

Appendix A

(normative appendix)

The calculation of the 5% and 95% denominations

##### A.1 Overview

This appendix provides for the calculation of the 5% and 95% denominations.

##### A.2 symbol

The common symbols used in this appendix are as follows:

m – the number of specimens taken by each model in the vertical and horizontal directions

X5% – the next 5% of the sample

S – Standard deviation calculated from test or measurement values

Sw, j — the standard deviation X95% of the sample for the sample — the upper 95% bit value of the sample

Xij- Test or measurement

jx – the arithmetic average of m individual test values or measurementsobtained from a single model j

tm – At the α of the significance level, the m-block specimen is normally distributed on one side of the t-value

##### A.3 calculation

A.3.1 Average per model (board average)

The arithmetic mean of the m test values in the model j  is calculated by formula (A.1):

The standard deviation of the standard deviation model in the formula.

A.3.2 board j in the m test value of the standard deviation is calculated by formula (A.2):

A.3.3 The 5% bit value of the normal distribution of the performance of the model and the 5% bit value and the 95% bit of the normal distribution of the performance of each model test performance are calculated by formula (A.3) and formula (A.4), respectively:）

GB/T 11718-202X

Note: In the formula CV is the coefficient of variation,j, x/CVjwS, if the coefficient of variation CV is less than 0.08, then the CV takes 0.08 for the formula (A.. 3) And type (A. 4）

##### A.4 Calculated

Tm is the normaldistribution t value on one side of the m-block specimen at the α of the significance level, and 89.1m-t when m-8, and when m-1280.1m=t.