A manager is holding the following portfolio:
Stock Amount Invested Beta
1 $300,000 0.6
2 $300,000 1.0
3 $500,000 1.4
4 $500,000 1.8
The risk free rate is 6% and the portfolio's required rate of return is 12.5%. The manager would like to sell all of the holdings of stock 1 and use the proceeds to purchase more shares of stock 4. What would be the portfolio's required rate of return following this change?