ed moura has $11000 invested in 6%. how much additional money should he invest in certificates of deposit paying 3% so that the average return on the two investments is 4%

To solve this problem, we can set up an equation based on the given information.

Let's assume that the additional amount Ed Moura invests in the certificate of deposit is x dollars.

The interest earned from the initial investment at 6% is calculated as 0.06 * $11,000 = $660.

The interest earned from the additional investment at 3% is calculated as 0.03 * x.

The total interest earned from both investments at an average return of 4% is calculated as 0.04 * ($11,000 + x).

Now we can set up the equation:

660 + 0.03x = 0.04(11,000 + x)

To solve for x, we can simplify the equation:

660 + 0.03x = 440 + 0.04x

0.04x - 0.03x = 440 - 660

0.01x = 220

x = 220 / 0.01

x = $22,000

So, Ed Moura should invest an additional $22,000 in certificates of deposit to achieve an average return of 4% on his total investment.