Nonconstant Growth Valuation

Holt Enterprises recently paid a dividend, D₀, of $2.75. It expects to have nonconstant growth of 18% for 2 years followed by a constant rate of 6% thereafter. The firm's required rate of return is 12%.

a. How far away is the horizon date?

b. What is the firm's horizon, or continuing, value?

c. What is the firm's intrinsic value today, P₀?

Please show all the math worked out! Thank you.