Suppose the X is a continuous random variable whose probability density
function is given by
$$
f(x) = \begin{cases}
kx, & 0 \le x < 3, \\
2 - \frac{x}{2}, & 3 \le x \le 4, \\
0, & \text{otherwise}
\end{cases}
$$
(a) What is the value of k?
(b) What is the cumulative distribution function of X, F(x)?
(c) Find P {1 < X ≤ 2}