T.DIST in Collabora Office: Calculate Student t Cumulative Probability or Density
Use Collabora T.DIST with signed t values, explicit cumulative mode and reproducible symmetry and probability-band checks.
Verification status: See the evidence and test scope described in this guide. How formula examples are checked
Quick answer: =T.DIST(1;10;1) has independently expected result approximately 0.829553434. It is the left-tail cumulative probability through t=1 for ten degrees of freedom.
Syntax and arguments
=T.DIST(Number; DegreesFreedom; Cumulative)
Number is the signed evaluation point. DegreesFreedom selects the t distribution. Cumulative is required: use zero or FALSE for density and one or TRUE for cumulative probability. This guide supplies the flag explicitly in every forward calculation.
Left-tail probability means P(T<=x). It increases with x and is one half at zero. Density instead measures the height of a continuous probability curve; it is not the probability of exactly that point. The function does not compute a t statistic from a dataset.
The cited Collabora help supplies the three-argument syntax and its t=1, ten-degree example. The corroborating current source accepts signed Number values and approximately floors DegreesFreedom before requiring at least one. Use positive integer degrees in the examples rather than relying on a fractional conversion.
Example 1: build a signed cumulative table
Put -2, -1, 0, 1, 2 in A2:A6. Enter =T.DIST(A2;10;1) in B2 and fill down. Independent targets are approximately 0.036694017, 0.170446566, 0.5, 0.829553434 and 0.963305983.
Negative evaluation points are meaningful: they lie below the distribution’s center. Replacing every Number with ABS(Number) would destroy the left-tail interpretation for those rows.
For a symmetric t model, cumulative probabilities at x and -x sum to one. Compare B2+B6 and B3+B5; each independently targets one. This symmetry is about the distribution, not about the symmetry of a particular observed dataset.
Example 2: distinguish density values
Enter =T.DIST(A2;10;0) in C2 and fill down. Independent densities are approximately 0.061145766, 0.230361989, 0.389108384, 0.230361989 and 0.061145766.
The densities are symmetric rather than cumulative. C3 and C5 are equal even though B3 and B5 are different. At t=0, the density is about 0.389108384, while the cumulative probability is 0.5.
Use separate headers for density and probability. Applying percentage formatting to both columns would hide their different meanings rather than resolve them.
Advanced application: calculate an interval probability
For ten degrees of freedom, =T.DIST(2;10;1)-T.DIST(-2;10;1) has independent target approximately 0.926611965. The remaining two-tail probability outside -2 to 2 is approximately 0.073388035.
A continuous model assigns zero probability to an individual endpoint, so changing strict to inclusive inequalities at these endpoints does not change the interval probability. That reasoning does not transfer directly to discrete-count distributions.
Advanced application: verify an inverse threshold
Put =T.INV(0.975;10) in F2. Its independent target is approximately 2.228138852. Then =T.DIST(F2;10;1) targets 0.975, while the right-tail probability is 0.025.
Use the stored F2 result rather than a rounded copy. A two-sided 5% threshold divides the total excluded probability across both tails; it is not the same as the 95th percentile.
Errors and troubleshooting
Check the cumulative flag before interpreting a number as a probability. A missing required flag is not an instruction to choose a default. Validate positive integer degrees and keep the sign of the evaluation point when a left-tail event is intended.
Source corroboration does not certify all native coercions, localized error messages or extreme-tail accuracy. A tail probability is conditional on a model; it is not the probability that a hypothesis is true. The statistic, degrees of freedom and assumptions require a separate justification.
Availability and evidence
The exact function is documented in Collabora Office 26.04 desktop help. That documentation snapshot was retrieved on 2026-10-13 and hash-verified on October 15, 2026. It does not establish Online or mobile support. First introduction and last functioning release are unknown in this evidence.
Additional implementation statements come from Collabora’s current engine source, retrieved October 15, 2026. This moving-main source is corroboration, not a pinned desktop 26.04 binary or a native execution. No native Collabora Office run occurred. Worked outputs are independent mathematical expectations.
Formulas use English names and semicolon separators. The help identifies namespace COM.MICROSOFT.T.DIST, outside its cited OpenFormula 1.3 standard; that does not establish identical behavior in another application.