A researcher wants to know whether the mean length of the stay for-profit is different from the mean length of the stay not-for-profit hospitals. He randomly selected 20 individuals in the for profit hospital and matched them with 20 individuals in the not-for-profit hospital by diagnosis. Determine this sample is independent or dependent.

I'm guessing dependent because it's a yes or no answer i.e it has to be one or the other
You might want to check if I've got my definition of a dependent answer right