*15*

When you conduct an F test, you will get an F statistic as a result. To determine if the results of the F test are statistically significant, you can compare the F statistic to an **F critical value**. If the F statistic is greater than the F critical value, then the results of the test are statistically significant.

The F critical value can be found by using an F distribution table or by using statistical software.

To find the F critical value, you need:

- A significance level (common choices are 0.01, 0.05, and 0.10)
- Numerator degrees of freedom
- Denominator degrees of freedom

Using these three values, you can determine the F critical value to be compared with the F statistic.

**How to Find the F Critical Value in Excel**

To find the F critical value in Excel, you can use the** F.INV.RT()** function, which uses the following syntax:

**F.INV.RT**(probability, deg_freedom1, deg_freedom2)

**probability:Â**The significance level to use**deg_freedom1**: The numerator degrees of freedom**deg_freedom2**: The denominator degrees of freedom

This function returns the critical value from the F distribution based on the significance level, numerator degrees of freedom, and denominator degrees of freedom provided.

For example, suppose we would like to find the F critical value for a significance level of 0.05, numerator degrees of freedom = 4, and denominator degrees of freedom = 6.Â

In Excel, we can type the following formula: **F.INV.RT(0.05, 4, 6)**

This returns the valueÂ **4.5337**. This is the critical valueÂ for a significance level of 0.05, numerator degrees of freedom = 4, and denominator degrees of freedom = 6.

Note that this also matches the number we would find in the F distribution table withÂ Î± = 0.05, DF1 *(numerator degrees of freedom)* = 4, and DF2 *(denominator degrees of freedom)* = 6.

**Cautions on Finding the F Critical Value in Excel**

Note that theÂ **F.INV.RT()** function in Excel will throw an error if any of the following occur:

- If any argument is non-numeric.
- If the value forÂ
*probabilityÂ*is less than zero or greater than 1. - If the value forÂ
*deg_freedom 1Â*orÂ*deg_freedom2Â*is less than 1.

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