How to Use the FINV Function in SAS (With Examples)

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 print data=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 print data=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 F distribution table 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.