For a group of n people, k of whom are of the same sex, the (n-k)/n expression yields an index for a certain phenomenon in group dynamics for members of that sex. For a group that consists of 20 people, 5 of whom are females, by how much does the index for the females exceed the index for the males in the group?	Choices:	A) 0.05	B) 0.0625	C) 0.5	D) 0.25	E) 0.6
Index for females = (20-5)/20 = 3/4= 
<gadget id="calculator">3/4</gadget>
<output>3/4 = around 0.75</output>
0.75   Index for males= (20-15/20 = 1/4= 
<gadget id="calculator">1/4</gadget>
<output>1/4 = around 0.25</output>
0.25   Index for females exceeds males by   0.75 - 0.25= 
<gadget id="calculator">  0.75 - 0.25</gadget>
<output>0.5</output>
0.5   Answer: 0.5
<result>C</result>
For a group of n people, k of whom are of the same sex, the (n-k)/n expression yields an index for a certain phenomenon in group dynamics for members of that sex. For a group that consists of 20 people, 5 of whom are females, by how much does the index for the females exceed the index for the males in the group?