The T.INV.2T function in Google Sheets is a statistical function that computes the critical value for the two-tailed Student’s t-distribution. This function is particularly useful in hypothesis testing and confidence interval estimation, allowing users to determine the t-value associated with a given probability and degrees of freedom.

Syntax

T.INV.2T(probability, degrees_freedom)

• probability: The probability associated with the two-tailed t-test (a value between 0 and 1).
• degrees_freedom: The number of degrees of freedom, which is typically the sample size minus one.

Example #1

=T.INV.2T(0.05, 10)

This function returns the t-value that corresponds to a 0.05 probability level with 10 degrees of freedom. For this input, the result would be approximately 2.228.

Example #2

=T.INV.2T(0.01, 15)

Here, the function calculates the t-value at a 0.01 probability level with 15 degrees of freedom. The result would be roughly 2.947, indicating a higher level of significance.

Example #3

=T.INV.2T(0.10, 20)

This example computes the critical t-value for a 0.10 significance level with 20 degrees of freedom, resulting in approximately 1.645.

Error handling

• NUM!: This error occurs if the ‘probability’ value is not between 0 and 1 or if the ‘degrees_freedom’ is less than 1.
• VALUE!: This error indicates that either the ‘probability’ or ‘degrees_freedom’ arguments are not numeric values.

Conclusion

In summary, the T.INV.2T function is an essential tool in statistical analysis, allowing users to find critical t-values for hypothesis testing. Understanding its syntax and potential errors is crucial for effective application in research and data analysis.