You will have to tweak it to make it work for your game, but it functions correctly.
The text attribute "Word" was just used inmy example because thats what i set my text to. However you used a list so instead of using "get width of word" you would use something like "get width of (get item # 0 in list) + (get item # 1 in list) + (get item # 2 in list)".