Answer:
2019.
Step-by-step explanation:
We have been given that for the years from 2002 and projected to 2024, the national health care expenditures H, in billions of dollars, can be modeled by [tex]H = 1,500e^{0.053t}[/tex] where t is the number of years past 2000.
To find the year in which national health care expenditures expected to reach $4.0 trillion (that is, $4,000 billion), we will substitute [tex]H=4,000[/tex] in our given formula and solve for t as:
[tex]4,000= 1,500e^{0.053t}[/tex]
[tex]\frac{4,000}{1,500}=\frac{ 1,500e^{0.053t}}{1,500}[/tex]
[tex]\frac{8}{3}=e^{0.053t}[/tex]
[tex]e^{0.053t}=\frac{8}{3}[/tex]
Take natural log of both sides:
[tex]\text{ln}(e^{0.053t})=\text{ln}(\frac{8}{3})[/tex]
[tex]0.053t\cdot \text{ln}(e)=\text{ln}(\frac{8}{3})[/tex]
[tex]0.053t\cdot (1)=0.9808292530117262[/tex]
[tex]\frac{0.053t}{0.053}=\frac{0.9808292530117262}{0.053}[/tex]
[tex]t=18.506212320[/tex]
So in the 18.5 years after 2000 the expenditure will reach 4 trillion.
[tex]2000+18.5=2018.5[/tex]
Therefore, in year 2019 national health care expenditures are expected to reach $4.0 trillion.