Answer: There are 980 degrees of freedom for the within subjects factor.
Step-by-step explanation:
Since we have given that
Number of groups = 20
Number of participants in each group = 50
So, number of participants in 20 groups is given by
[tex]20\times 50\\\\=1000[/tex]
As we know that
Degrees of freedom for the within subjects factor would be
[tex]v=n-k\\\\v=1000-20\\\\v=980[/tex]
Hence, there are 980 degrees of freedom for the within subjects factor.