For ANOVA, the test statistic is called an __ test statistic (also called an __-ratio), which is the variance   (2)   samples (a.k.a., variation due to treatment) divided by the variance   (3)   samples (a.k.a., variation due to error or chance).

The first two blanks are completed with the letter this author uses for the ANOVA test statistic. What is this letter?

Fill in blank (2):

Fill in blank (3):