I have two questions that I need help with my coursework. I have an answer but I am not sure whether they are correct. I was wondering whether you could answer it as well and we can compare answers to see if I am correct or not and if not, how I could correct myself.

3a) Calculate the Macaulay Duration of a 6% annual coupon bond with a face value of a 1000 and three years to maturity. Assume that all market interest rates are 7%.

b) Consider the bond in 3a. Calculate the expected price change if interest rates drop to 6.75%. Then, calculate the actual price change using the discounted cash flow method.

If you could please help then that would be great! Thank you.