Yes.
The domain of the Normal distribution is the whole of the real line. As a result the horizontal axis is asymptotic to the Normal distribution curve. The curve gets closer and closer to the axis but never, ever reaches it.
No.
yes it can be negative.
Yes, if you are averaging numbers that include negative numbers.
It depends what you mean by "normal". If by normal you are asking if autistic people will ever become neurotypical - no, that's like asking if black people can ever become white. Who wants to be normal anyway?
This is not likely to happen - although there is currently lots of theoretical research on the topic.
Negative, ghostrider.
Yes.
no
Acceleration is negative when the object is moving in the opposite direction. on a graph the line would be in the negative quadrant.
negative*negative=positive negative/positive=negative negative\negative=positve negative-positive=change the sign to a plus and then change the number after the sign and get your answer negative +positive=which ever numbr is bigger minus positive+positive=positive
No. Neither the standard deviation nor the variance can ever be negative.