Collins Hickey Johnston (August 29, 1859 – December 29, 1936) was an American football player, medical doctor, surgeon, and civic leader in Grand Rapids, Michigan. He was a graduate of the University of Michigan where he played college football for the 1879 Michigan Wolverines football team, the first football team to represent the University of Michigan. Using only the above description and what you know about the world, "Collins Hickey Johnston was eighteen years old when he began attending the University of Michigan." is definitely correct, incorrect, or inconclusive? 