It's skewed to the left, just the opposite to what you think left and right should mean.
It depends on what you are told about borders. I think it should go between 50 and 60, but it could also go between 60 and 70. The only thing I can tell you for certain is that it is not both. No one talks about what you do if data lands on a border.
Having said that, the answer to the third one is 5