Given $n _ { 1 } = 15 , n _ { 2 } = 21 , \mathrm {~S} = 258.5 , \text { and } H _ { 1 } : m _ { 1 } \neq m _ { 2 } ,$

Multiple Choice

Given $n _ { 1 } = 15 , n _ { 2 } = 21 , \mathrm {~S} = 258.5 , \text { and } H _ { 1 } : m _ { 1 } \neq m _ { 2 } ,$ compute $\sigma _ { s }$

A) -0.61
B) 277.5
C) 37
D) 31.16