$$\color{rgb(0,0,0)}X \text{ suit la loi normale }N\left( \mu;\sigma^2 \right) = N(7 ;2^2)$$

$$\color{rgb(0,0,0)}a=$$

$$\color{rgb(0,0,0)}= 10$$

$$\color{rgb(0,0,255)}P\left( {X < 10 } \right) \approx 0.9332 $$

$$\color{rgb(0,0,255)}a $$

$$\color{rgb(0,0,0)}= 12$$

$$\color{rgb(0,0,0)}\mu = $$

$$\color{rgb(0,0,0)}= 7$$

$$\color{rgb(0,0,0)}\sigma=$$

$$\color{rgb(0,0,0)}= 2$$

$$\color{rgb(0,0,255)}\Rightarrow P(X < a)$$

$$\color{rgb(0,0,255)}\Rightarrow P( X \ge a)$$

$$\color{rgb(0,0,255)}\Rightarrow P(a \le X \le b)$$