## 3 Results
### Variability of Features and Their Contribution to the Total Variance
Negative values of kurtosis (in our research, these are: dry matter and starch yield, the moisture content of chips, and moist places in chips) mean that their distribution is more flattened, which may indicate greater variability in the data or the presence of extreme values. Kurtosis is one measure of the shape of a distribution and is used to determine whether a sample is more flat or conical than a normal distribution. Skewness is a measure of the asymmetry of the sample distribution, which is how much the distribution is shifted in one direction from the mean value. It also tells you whether the distribution is more concentrated around one side of the mean or the other. If the sample distribution is symmetric, the skewness is 0. However, if the values at one end of the distribution are more clustered than the other, then the distribution is skewed. Skewness can be positive or negative, depending on the direction of the asymmetry. Positive skewness means that the distribution is shifted to the right and the tails of the distribution are longer on the right side. The mean values are then lower than the median and outliers appear on \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Specification** & **x1** & **x2** & **x3** & **x4** & **x5** & **x6** & **x7** & **x8** & **x9** & **x10** \\ \hline Mean & 20.38 & 8.79 & 15.36 & 6.61 & 7.90 & 3.80 & 3.80 & 2.07 & 2.60 & 23.17 \\ Median & 20.13 & 8.74 & 15.10 & 6.57 & 7.87 & 3.83 & 3.81 & 2.11 & 2.11 & 23.33 \\ Standard deviation & 3.00 & 2.54 & 2.18 & 1.86 & 0.43 & 0.49 & 0.45 & 0.25 & 0.93 & 1.75 \\ Kurtosis & 0.48 & \(-\)0.46 & 0.44 & \(-\)0.50 & 0.13 & 0.24 & 0.54 & \(-\)1.12 & \(-\)0.74 & 0.22 \\ Skewness & 0.68 & 0.26 & 0.69 & 0.25 & \(-\)0.16 & 0.32 & 0.44 & \(-\)0.04 & 0.58 & 0.69 \\ Range & 14.53 & 11.55 & 10.90 & 8.60 & 1.78 & 2.00 & 1.89 & 1.14 & 6.56 & 6.39 \\ Minimum & 14.53 & 3.78 & 10.90 & 2.90 & 6.93 & 2.89 & 3.00 & 1.50 & 0.00 & 21.05 \\ Maximum & 29.07 & 15.33 & 21.80 & 11.50 & 8.71 & 4.89 & 4.89 & 2.64 & 6.56 & 27.44 \\ Coefficient of variation (\%) & 14.70 & 28.85 & 14.22 & 28.12 & 5.50 & 12.85 & 11.93 & 12.07 & 35.78 & 7.55 \\ \hline \hline \end{tabular}  
* x1—dry matter content (%); x2—yield of dry matter (t-ha\({}^{-1}\)); x3—starchant content (%); x4—starch yield (t-ha\({}^{-1}\)); x5—color of chips (9° scale); x6—organole assessment of chips (on a scale of 5); x7 (visual assessment of chips (5° scale); x8—moisture content of chips (%); x9—moist places (%); x10—fat content in chips (%).  
\end{table} 
Table 8: Descriptive statistics of the content of dry matter, starch, yield, and quality characteristics of chips. the right. On the other hand, negative skewness (color and moisture of the chips) means that the distribution is shifted to the left, and the tails of the distribution are longer on the left side. The mean values are then higher than the median and outliers appear on the left. Skewness is one of the parameters characterizing the distribution of the sample and may affect the interpretation of the test results (Table 8). The coefficient of variation (CV) is a measure of sample variation or dispersion that is used to compare the variation between different data sets. The coefficient of variation is expressed as a percentage of the mean, meaning that the higher the coefficient of variation, the greater the relative variability of the sample relative to its mean. It is especially useful when comparing variabilities between data sets with different average values. The smaller the coefficient of variation, the lower the relative variation of the sample. The most stable feature among those assessed was the color of the chips (V = 5.5%). Similar variability was observed for the fat content in the chips (V = 7.5%), and the most variable feature was the moist places in the chips (V = 35, 78%). The variability of dry matter and starch and their yields were very similar (V = 14.7% for DM and 14.22% for starch, respectively; for dry matter yield V = 28.85%, and for starch yield V = 28.12%).