The formula for simple interest is:

Where
i is the interest amount
P is the initial amount invested
r is the rate of interest [in years]
t is the time period [in years]
We are given
i = 501 [wants to achieve interest of 501 dollars\
P = 3692
r is what we need to figure out
t is 7
Substituting, we get:

Mulitplying by 100, we get the percentage interest rate.
0.019385 * 100 = 1.94%