To find the amount invested at 4%, we need to set up an equation using the given information. Let's solve it step by step.
Let's suppose the amount invested at 4% is x.
The total amount invested is $7500, so the amount invested at 5% is the remainder, which is (7500 - x).
Now we can set up the equation using the total interest earned:
Total interest = Interest earned from the amount invested at 5% + Interest earned from the amount invested at 4%
$346.50 = (7500 - x) * 0.05 + x * 0.04
Simplifying the equation:
346.50 = 375 - 0.05x + 0.04x
Combine like terms:
346.50 = 375 - 0.01x
Now, let's isolate x by subtracting 375 from both sides:
346.50 - 375 = -0.01x
-28.50 = -0.01x
To solve for x, divide both sides of the equation by -0.01:
x = -28.50 / -0.01
x = 2850
So, the amount invested at 4% is $2850.