Question 977939
It is like a coin toss.  I could argue that if you knew the price of the stock and where it had been traded, you would have a much better chance of knowing what the probability is.

But if I have no idea of the historical price of Google stock and a buy a share, the probability of its closing less than the mean is 50% assuming a normal distribution.  I would prefer the median, which would definitely make it 50%.