STATS2

• The t distribution (aka, Student's t-distribution) is a probability distribution that is used to estimate population parameters when the sample size is small and/or when the population variance is unknown.
• It was developed by Willam Sealy Gosset in 1908.
• The formula is used when n < 30 and the population standard deviation is unknown.
• The t-Distribution with n-1 degrees of freedom.