问题如下：
The dividend policy of Berkshire Gardens Inc. can be represented by a gradual adjustment to a target dividend payout ratio. Last year Berkshire had earnings per share of $3.00 and paid a dividend of $0.60 a share. This year it estimates earnings per share will be $4.00. Find its dividend per share for this year if it has a 25 percent target payout ratio and uses a five-year period to adjust its dividend.
选项：
A.$0.68.
B.$0.80.
C.$0.85.
解释：
A is correct.
Expected dividend = Previous dividend + (Expected earnings ×Target payout ratio – Previous dividend) × Adjustment factor)=$0.60+（$4×0.25-$0.6）×0.2=$0.68
这个题根本不对。
我们能做的是根据去年 d=0.2 和 5年后d=0.25，通过插值法得到今年d=0.21 然后再通过今年的eps=4，算出分红等于0.84
不太能理解书上的公式是怎么推导出来的。
