The given mixed numbers are:

The first thing we need to do is convert it into improper fractions, as follows:

Now, continue with 2 1/4:

In order to plot them on the number line, for the first fraction 3/2, we need to divide the unity into 2 equal parts, and then count 3 of these divisions, that would be 1 1/2 or 3/2, is the same:
Now for the 2 1/4 or 9/4 (they are the same), we need to divide the unity into 4 equal parts and then count 9 of these divisions, then: