T DISTRIBUTION

[t distribution] n (ca. 1957): a probability density function that is used esp. in testing hypotheses concerning means of normal distributions whose standard deviations are unknown and that is the distribution of a random variable equated to a fraction whose numerator is u times the square root of n and whose denominator is v where u and v are themselves independent random variables and u has a normal distribution with mean 0 and a standard deviation of 1 and the square of v has a chi-square distribution with n degrees of freedom--called also student's t distribution