How to Use the F Distribution with F.DIST.RT in Excel

Use F.DIST.RT to compare the variability of two processes and to read an ANOVA F statistic as a p-value.

You will learn to

• Test whether one process varies more than another
• Get the p-value of an ANOVA F statistic
• Run a two-tailed variance test

How it works

The F distribution describes the ratio of two variances. F.DIST.RT(F,df1,df2) returns the right-tail probability, which is the p-value for "is the first variance bigger than the second?" Compute F as SD1² ÷ SD2², with df1 = n1 − 1 and df2 = n2 − 1.

The same function reads the F statistic from a one-way ANOVA, using df1 = groups − 1 and df2 = total observations − groups. For a two-tailed variance test, double the smaller of the two tails.

=F.DIST.RT(2.25,12,15)