Va rog dau coroana ex 3 îmi trebuie urgent!!! Dau 20 puncte!!

1+2+2+3+6+5+3+3 = 23 elevi
6+5+3+3 = 17 elevi
Ma = (3×1+4×2+5×2+6×3+7×6+8×5+9×3+10×3)/23 = (3+8+10+18+42+40+27+30)/23 = 178/23 = 7,74