Restex has a debt-equity ratio of 0.73, an equity cost of capital of 13%, and a debt cost of capital of 8%. Restex's corporate tax rate is 30%, and its market capitalization is $225 million.

a. If Restex's free cash flow is expected to be $4 million one year from now and will grow at a constant rate, what expected future growth rate is consistent with Restex's current market value?

b. Estimate the value of Restex's interest tax shield.