In a Simple Linear Regression Analysis,the Following Sums of Squares

Multiple Choice

In a simple linear regression analysis,the following sums of squares are produced: $\sum \left( Y _ { i } - \bar { Y } \right) ^ { 2 } = 400 , \sum \left( Y _ { i } - Y \right) ^ { 2 } = 80 , \sum \left( \bar { Y } _ { i } - \bar { Y } \right) ^ { 2 } = 320$
The proportion of the variation in Y that is explained by the variation in X is:

A) 20%
B) 80%
C) 25%
D) 50%
E) None of the above