... αp + βp1.F1 + βp2.F2 + βp3. F3 + εptrong đó : αp = 1 /3 .5 + 1 /3. 5 + 1 /3. 5 = 5%βp1 = 1 /3. 1 + 1 /3. 1, 2 + 1 /3. 0 ,3 = 0, 833 3% βp2 = 1 /3. [-2] + 1 /3. 0 + 1 /3. 0,5 = -0,5%βp3 = 1 /3. [-0,2] ... 02 ,1= ρ52 211 2 ,12 222 212 1 21 δρδδδwwwwdm++== 20.25,0 .10 .75,0.220.25, 010 .75,02222++= 9%Với : 12 ,1= ρ=> 2 211 2 ,12 222 212 1 21 δρδδδwwwwdm++== 20.25,0 .10 .75,0 .1. 220.25, 010 .75,02222++= 12 ,5%Với : 12 ,1 =ρ=> 2 211 2 ,12 222 212 1 21 δρδδδwwwwdm++== ... %98.75, 012 .25,0..222=+=+=YYXXdmrwrwrYYXXYXYYXXdmwwwwδδρδδδ.....2..2222222222++=%6,45,0.75,0.8.25,0.2,0.25.75,08.25,02222=++Danh mục 3: %7 53= Xw ;%2 53= Yw => %11 8.25, 012 .75,0. .33 3=+=+=YYXXdmrwrwrYYXXYXYYXXdmwwwwδδρδδδ.....2. .33 32 232 233 ++= %37 ,65,0.25,0.8.75,0.2,0.25.25,08.75,02222=++b) Phát biểu tập hợp hiệu quả...