## Precalculus (6th Edition) Blitzer

a. $P(x)= 2.92x+236$ (millions) b. $R(x)=\frac{1.48x + 115.1}{2.92x+272}$ c. $y\approx0.51$
a. The total population is the sum of the two functions: $P(x)=M(x)+F(x)=1.48x + 115.1+1.44x + 120.9=2.92x+236$ (millions) b. The function of men in the total population is given by $R(x)=\frac{1.48x + 115.1}{2.92x+272}$ c. To obtain the horizontal asymptote of the above function, let $x\to\infty$ We have $y=\lim_{x\to\infty}\frac{1.48 + 115.1/x}{2.92+272/x}=\frac{1.48}{2.92}\approx0.51$ This means that the percentage of men in the US population will approach 0.51 over time.