College Algebra Homework Help

(There is a graph that I would need to enclose an image of) 

a. Write a function that models the difference between the female U.S. population and the male U.S. population for the years shown in the bar graph.

b. Use the function from part (a) to find how many more women than men there were in the U.S. population in 2005.

c. Does the result in part (b) overestimate or underestimate the actual difference between the female and male population in 2005 shown by the bar graph? By how much?

The link to the graph is:

http://www.mediafire.com/view/ufd2ky2f3zbi54v/image.jpeg