You can use the FINV function in SAS to find critical values from the F distribution.

This function uses the following basic syntax:

FINV(p, ndf, ddf)

where:

• p: 1 – the significance level
• ndf: The numerator degrees of freedom
• ddf: The denominator degrees of freedom

The following example shows how to use the FINV function in practice to calculate F critical values.

Example: How to Use FINV Function in SAS to Calculate F Critical Values

Suppose we would like to find the F critical value for a significance level of 0.05, numerator degrees of freedom = 6, and denominator degrees of freedom = 8. 

We can use the FINV function to calculate this value:

/*create dataset that contains F critical value*/
data my_data;
    critical_val=finv(.95, 6, 8);
    put critical_val=;
run;

/*view results*/
proc printdata=my_data; 

The F critical value for a significance level of 0.05, numerator degrees of freedom = 6, and denominator degrees of freedom = 8 is 3.58058.

Thus, if we’re conducting some type of F test then we can compare the F test statistic to 3.58058.

If the F statistic is greater than 3.58058, then the results of the test are statistically significant.

It’s worth noting that smaller values for the significance level will lead to larger F critical values.

For example, consider the F critical value for a significance level of 0.01, numerator degrees of freedom = 6, and denominator degrees of freedom = 8:

/*create dataset that contains F critical value*/
data my_data;
    critical_val=finv(.99, 6, 8);
    put critical_val=;
run;

/*view results*/
proc printdata=my_data; 

The F critical value for a significance level of 0.05, numerator degrees of freedom = 6, and denominator degrees of freedom = 8 is 6.37068.

Note: You can also use the to find critical values by hand. The values that you find in the table will match the ones calculated by the FINV function in SAS.

The following tutorials explain how to perform other common tasks in SAS: