In the Scheffe Test, If $\bar { X } _ { 2 } = 8$

Multiple Choice

In the Scheffe test, if $\bar { X } _ { 2 } = 8$ for a group size $n _ { 2 } = 8 , \bar { X } _ { 4 } = 13$ for a group size $n$ and the within-group variance $s _ { w } { } ^ { 2 } = 16$ , then the $F _ { S }$ test value for comparing these two groups is equal to

A) -1.25
B) 3.91
C) 6.25
D) 1.56