My professor gave us these problem and I can't solve it. He didn't really explain well the lesson on normal distribution so I'm just so lost with this. Hope somebody can help.

1.) Let X be a continuous random variable defined on the interval [0, 2]. The PDF of X is given by

$\displaystyle f(x)= \frac 1 2 X$

a. Graph the PDF of X

b. Find P(X>1.5)

c. Find P(X≤1.5)

d. Find P(0.5<X<1.5)