CFA一级中这道计算题题如何解答？

CFA每个科目中都会出现计算题，除了道德科目，在备考中不能忽视计算题的计算，对于很多考试题都有他的解题技巧，学会是很重要的，在CFA一级中下面这道题如何解答？

Using the BEY (bond-equivalent yield) spot rates for U.S. Treasury yields provided in the following table, the 6-month forward rate one year from now on a bond-equivalent yield basis is closest to:

A. 4.41%

B. 2.20%

C. 2.30%

Answer：A

Assume:

xfy represents x-period forward rate y-period from now;

Z x+y represents (x+y)-period spo

We have (1+Z x+y)x+y=(1+Zy)y (1+xfy)x

6-month forward rate one year from now in this case is 1 period forward rate 2-period from now.

All spot rates are given on a BEY basis and must be divided by 2 in the calculation:

(1+1f 2)1 (1+0.023/2)2=(1+0.03/2)3

1f 2=0.022038

On a BEY basis, the forward rate is 0.022038*2=4.41%