An experimenter has run a two-factor factorial with factor A…

An experimenter has run a two-factor factorial with factor A (3 levels) and B (2 levels) both random. There are 2 replicates. A partial ANOVA table is shown below.   Factor Sum of Squares Degrees of Freedom A 25.00 2 B 60.75 1 AB 30.00 2 Error 10.00 6 Total 100.75 11   The estimate of the variance component for the main effect of B is