My assignment is to find T critical values for a confidence level and a number n.

For instance, find the T critical value for the confidence percentile 95% and n=17.

I know how to find these values when there is a standard deviation known, but I have no idea what to do without one. Help is much obliged

The standard deviation is irrelevant when getting a critical value for the t-distribution.

Consult this: http://www.statsoft.com/textbook/sttable.html#t

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