7. When opening an IRA account, investors have two options. With a regular IRA account, funds added are not taxed initially, but are taxed when withdrawn. With a Roth IRA, the funds are taxed initially, but not when withdrawn. If an investor wants to contribute $15,000 before taxes to an IRA, what will be the difference after 30 years between the two options? Assume that the investor is currently in the 25% tax bracket, and that the IRA will earn 6% per year