Compound to simple time signatures

[eel05]

Hello, I've come across this question and I'm a little puzzled about the last bar. The question was to change the time from compound to simple time without changing the rhythm. I'm a bit stumped as to why the minims haven't changed to crochets and why the crotchets didn't change to minims!!

Any words of wisdom on this would be greatly appreciated!!

[j_menz]

To convert a/b time to c/d time you take each note (x) and the new note (y) is :

y = (c/a) * (b/d) * x

So in this case

y = 3/9 * 4/2 x
   = 1/3 * 2 * x
   = 2/3x

So, a dotted mimim changes to a minim.