TDIST
Formulas / TDISTCompute the probability for the student t-distribution.
TDIST(x,deg_freedom,tails)
- x - required, numeric value to evaluate the distribution on
- degrees_freedom - required, integer
- tails - required, 1 or 2, truncated to an integer
Examples
=TDIST(A2,A3,2)The TDIST function is used to calculate the probability of obtaining a given value from the t-distribution. In the example above, it returns the two-tailed distribution of values in cell A2, cell A3, and column 2 of the worksheet. The two-tailed distribution is the probability of a given value occurring in either tail of the t-distribution.
=TDIST(A2,A3,1)This example returns the one-tailed distribution of the difference between A2 and A3. The one-tailed distribution is the probability of a given value occurring in one tail of the t-distribution.
=TDIST(A2,A3,2, TRUE)The TDIST function can also be used to calculate the probability of obtaining a given value in the t-distribution. This returns the probability of the difference between A2 and A3 occurring in the two-tailed t-distribution.
=TDIST(A2,A3,3,TRUE)Finally, the TDIST function can be used to calculate the probability of obtaining a given value from the t-distribution. The example returns the three-tailed distribution of values in cell A2, cell A3, and column 3 of the worksheet. The three-tailed distribution is the probability of a given value occurring in any of the three tails of the t-distribution.
Summary
The TDIST function is used to calculate the probability of a student t-distribution in small sample data sets. It is available for backward compatibility and is improved by the T.DIST.2T and T.DIST.RT functions.
- The TDIST function returns the probability for the student t-distribution, and is used for small sample data sets.
- The new T.DIST.2T and T.DIST.RT functions provide improved accuracy.
Frequently Asked Questions
What are some important notes about using the TDIST function?
- The degrees of freedom must be greater than or equal to 1.
- The TDIST function assumes that the data is normally distributed.
- The TDIST function returns a one-tailed probability by default. To get a two-tailed probability, set the tails argument to 2.
