a)[tex]m_{clasei} = \frac{4\cdot 2 + 5\cdot 3 + 6\cdot 4 + 7 \cdot 5 + 8\cdot 6 + 9\cdot 3 + 10\cdot 2}{2 + 3 + 4 + 5 + 6 + 3 + 2} = \frac{8 + 15 + 24 + 35 + 48 + 27 + 20}{25} = \frac{177}{25} = \boxed{7.08}[/tex]
b) [tex]\displaystyle m_{clasei} > 7,40\Rightarrow \textrm{suma notelor} > 7.40 \cdot 25\Rightarrow \textrm{suma notelor} > 185\\186 - 177 = 9\Rightarrow\\\textrm{cei doi elevi care au nota 4 trebuiau sa mai ia impreuna inca 9 puncte}\Rightarrow 4 + \frac{9}{2} = 4 + 4.5 = 8.5\\\textrm{Trebuiau sa ia notele 8 si 9}[/tex]
