Find the quartiles :$Q_{1},Q_{2},Q_{3}$ of $X \in N(2,9)$
What I have tried : So for $Q_{1}$ for example , $Q_{1} =\frac{1}{4}$
$ X ~ (\mu,k^2) = P(X \le x)= P(kx+\mu \le x) = P(Z \le \frac{x-\mu}{k})=Φ (\frac{x-\mu}{k})$ in our case it will be $Φ (\frac{1/4-2}{3}) =Φ (-0.58)$.Then I should look at the normal distribution table for the answer and that is it ?