Answer:
Sarah has to invest $502,958.58 today.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
[tex]E = P*I*t[/tex]
In which E is the amount of interest earned, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
[tex]T = E + P[/tex]
In this question:
[tex]t = 35, I = 0.07, T = 1700000[/tex]
She has to invest P today.
[tex]T = E + P[/tex]
[tex]1700000 = E + P[/tex]
[tex]E = 1700000 - P[/tex]
So
[tex]E = P*I*t[/tex]
[tex]1700000 - P = P*0.07*34[/tex]
[tex]3.38P = 1700000[/tex]
[tex]P = \frac{1700000}{3.38}[/tex]
[tex]P = 502958.58[/tex]
Sarah has to invest $502,958.58 today.