A Data Set Contains the Observations 1, 6, 4, 5 $\sum x ^ { 2 } - \frac { \left( \sum x \right) ^ { 2 } } { 5 }$

Multiple Choice

A data set contains the observations 1, 6, 4, 5, 7. Find $\sum x ^ { 2 } - \frac { \left( \sum x \right) ^ { 2 } } { 5 }$

A) 21.2
B) 423.2
C) 101.6
D) 232.8