NORM.INV in Collabora Office: Find a Cutoff From a Normal Probability

=NORM.INV(Number; Mean; StDev)

Number is a cumulative probability, Mean the model center and StDev its standard deviation. All three arguments are required. In this syntax, Number is not a measurement such as 70; it is a probability such as 0.9 or 90%.

Use a positive StDev and probability strictly between zero and one for a finite real-valued normal quantile. The ideal normal distribution extends without bound, so its zero and one probability endpoints do not correspond to finite cutoffs. This is a mathematical domain statement; exact native endpoint errors are unverified here.

The result has the same units as Mean and StDev. A probability format belongs on the input, not on the returned measurement.

Put 0.9, 63 and 5 in B2:B4. Label them Cumulative probability, Mean and Standard deviation. Use =NORM.INV(B2;B3;B4) in B6.

The independent target is approximately 69.407757828. In B7 enter =NORM.DIST(B6;B3;B4;1); its target is the original 0.9. Keep the full B6 value for this check instead of typing its rounded display back into the formula.

The cutoff is a property of the specified normal model. It does not guarantee that exactly 90% of a finite sample will fall below it.

A threshold exceeded by 10% of this model is also the 90th-percentile cutoff, so its cumulative input is 1−0.10 = 0.9. Passing 0.10 directly would instead produce the lower 10th-percentile cutoff, approximately 56.592242172.

For an upper-tail exceedance probability of 1%, use =NORM.INV(0.99;63;5), independently approximately 74.631739370. Always translate the question into a left-tail probability before entering Number.

A central 95% interval leaves 2.5% in each tail. Under mean 100 and standard deviation 10, use =NORM.INV(0.025;100;10) and =NORM.INV(0.975;100;10).

The independent bounds are approximately 80.400360155 and 119.599639845. Applying NORM.DIST to the upper bound and subtracting its value at the lower bound yields 0.95 in the ideal model.

This is an interval containing 95% of a specified population distribution. It is not automatically a confidence interval for an estimated mean; that is a different statistical question requiring additional information.

A normal quantile can be reconstructed as Mean+StDev*NORM.S.INV(probability). At p=0.9, the standard-normal quantile is approximately 1.281551566, giving 63+5×1.281551566 ≈69.407757828.

Adding ten to Mean moves every quantile up by ten. Doubling StDev doubles the quantile’s displacement from Mean. These two controls help detect a mistaken mean or a variance entered where StDev belongs.

Check whether 90 was entered instead of 90%; the former is outside a probability’s valid range. Validate a positive standard deviation and numeric cells. Near probability endpoints, small changes in input can produce large cutoff changes, and extreme-tail accuracy needs deployment-specific testing.

The dedicated Collabora help does not establish every invalid-input error code or iteration tolerance. This guide provides independent quantile controls, not a captured target-application solver test.

The exact function is documented in Collabora Office 26.04 desktop help. Its source snapshot was retrieved on 2026-10-13 and hash-verified for this guide on October 15, 2026. Desktop documentation is not proof of Online or mobile support.

First introduced release and last functioning version are unknown. No native Collabora or WPS run occurred. The numerical values are independent mathematical expectations; they do not certify application-specific numerical tolerances, error codes or every edge case. Formulas use English names and semicolon separators.

The dedicated help identifies the namespace COM.MICROSOFT.NORM.INV and says this function is outside the cited OpenFormula 1.3 standard. That is a format-namespace disclosure, not evidence of identical behavior in another product. Retain the exact dotted name when checking an imported workbook.

• Collabora Office 26.04: NORM.INV.
• Editorial testing standards.