Update Statistics.ipynb

[svenaoki]

You've left the std to default, which seems to equals t 1, which generates a standard normal distribution

[dipranjan]

Hey, Thanks for pointing this out.

Rather than changing the question to call it Standard Normal Distribution, can you propose a solution where t = 1 is mentioned and we can call in the answer that for t=1 it is standard else not. That way readers will have a better answer to the same question.