توزيع بتاي تعميم يافته بهينه براي داده هاي درآمد و محاسبه ضريب جيني در استان خوزستان

Best generalized beta distribution for family incomes data and calculating Gini coefficient in Khozestan

Statistical distributions have important role in data analysis. Generalized distributions are very flexible distributions for several kinds of random variables. The most important distribution is the generalized beta distribution which is used for positive random variables. The generalized beta of the first kind "GB1" and second kind "GB2" are special cases of the generalized beta distribution. The "GB1" includes the "B1" and the "Generalized Gamma" as limiting cases. The "GB2" includes the "B2", the two Burr" distributions, Generalized Gamma, Fisk, Weibull and Log-normal distribution as special cases. Figure 4 shows the relation of the above distributions. By using the data of family incomes interval in Khozestan, the best distribution is estimated and the Gini coefficient is computed and the interpretation of the results are discussed.