Every time I get presented with this translation I write 'The machine is very powerful '. This seems the obvious translation to me. Of course it is always marked wrong yet all the other translations seem unnatural or contrived to me.
Kræfter is a plural (which is confusing from an English perspective), so it couldn't be meget. Just like in English you can't use 'much' with a plural. Why kræfter should be a plural is a question I cannot answer. It just is, I guess.
This one really irritates me. I always forget the translation given by Duolingo and write the obvious 'The machine is very powerful' and get it wrong. I must be on the tree for the 10th time due mainly to this exercise!