Answer
a. $-0.04x+5.8$ million
b. $4.8$ million.
c. underestimates by 0.2 million.
Work Step by Step
a. For the difference between the female and male populations, we have
$D(x)=F(x)-M(x)=1.44x+120.9-(1.48x+115.1)=-0.04x+5.8$ million
b. For year 2010, we have $x=2010-1985=25$ and $D(25)=-0.04(25)+5.8=4.8$ million.
c. Reading from the bar graph, we have $D_1=157-152=5$ million. Thus, the result from part-b underestimates the true value by 0.2 million.
