Students T-Test

Added functions for Students T-Test one sample and independant sets and a function to convert a t-value to a p-value. Not sure about the naming, if you would like me to change the function names and resubmit requrest, let me know. I have tests, I will add examples next week and I would like to add dependant sets after that.
Sorry, those were two different comments. The first is that the functions in this package accept weighted sample data. Mean, Variance, etc. The function signature you have written here only accepts unweighted data.

However, the above comment isn't really relevant. If you examine what this function does, it computes means and standard deviations and then does an operation with them. We already have functions that compute the mean and standard deviation. The mean and Std itself should be inputs to the function, not the sample values. Then, this function works like the rest of the functions in the package, including your implementation of OneSampleTTest above. By taking in means and stds, rather than the samples themselves, the function can support the final step of many operations ( a) mean known, std unknown, b) one mean known, the other unknown, both stds unknown, etc. etc.). It may be an extra line of code or two, but it's much more flexible. It has the additional bonus of being computationally faster if the user already needs the mean for something else.