1. **State the problem:** We need to find Stephen's height given that Stephen is taller than Marcus by half the difference between Kobe's height and Marcus's height. 2. **Given values:** - Kobe's height = $2.05$ m - Marcus's height = $1.89$ m 3. **Formula:** Stephen's height = Marcus's height + $\frac{1}{2} \times$ (Kobe's height - Marcus's height) 4. **Calculate the difference:** $$2.05 - 1.89 = 0.16$$ 5. **Calculate half the difference:** $$\frac{1}{2} \times 0.16 = 0.08$$ 6. **Add to Marcus's height:** $$1.89 + 0.08 = 1.97$$ 7. **Final answer:** Stephen is $1.97$ metres tall.