The F Distribution and the F-Ratio · Exercise 12

Girls from four different soccer teams are to be tested for mean goals scored per game. The entries in the table are the goals per game for the different teams. The one-way ANOVA results are shown in.
$$\begin{array}{cccc}\text{Team 1}& \text{Team 2}& \text{Team 3}& \text{Team 4}\\ \text{1}& \text{2}& \text{0}& \text{3}\\ \text{2}& \text{3}& \text{1}& \text{4}\\ \text{0}& \text{2}& \text{1}& \text{4}\\ \text{3}& \text{4}& \text{0}& \text{3}\\ \text{2}& \text{4}& \text{0}& \text{2}\end{array}$$

What is the df for the denominator?

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Introductory Statistics 2e · §13.2 The F Distribution and the F-Ratio · Exercise 12