Hello buddy,

Here is my number and verification.
I hope it helps. :)

1. 100*exp(-r*0.5)=96.8. 所以r=0.065.
2.和3的票息率不知道是对应什么。是终期给一次coupon还是每半年给一次coupon。如果是前者，答案是

2. 105.75*exp(-r)=99.56。所以r=0.0603

3. 107.5*exp(-r*1.5)=100.86。所以r=0.0418

如果是中间也有coupon可以依此类推，类似于算internal rate of return。

谢谢你的解答，完全正确。我能请教下解决这个问题的过程吗 如果您不介意并且有时间的话。

You are very welcome buddy. :)

Here is the speasheet.
Check it in detail please.

You can also get the identical result with bond formula.

The concept is simple:
1. Figure out the cash flow
2. Construct your equations
3. reverse engineering to verify your result

I hope it helps.
Good luck buddy. :)