这道题用P/b算出来的book value为什么不可以用？

问题如下：

At the conclusion of their meeting, Beckworth asks Castovan to value SSX using RI models. Selected fnancial information on SSX is presented in Exhibit 1:

Based on Exhibit 1, residual income for SSX is closest to:

选项：

€40.9 million

€90.2 million

€133.9 million

解释：

C is correct. The residual income can be calculated using net income and the equity charge or using net operating profit after taxes (NOPAT) and the total capital charge.

Residual income = Net income – Equity charge

Calculation of Net Income (values in millions):

Equity charge = Total assets × Equity weighting × Cost of equity

Equity charge = €4,000 million × 0.40 × 0.15 = €240 million

Therefore, residual income = €373.9 million – €240 million = €133.9 million.

Alternatively, residual income can be calculated from NOPAT as follows.

Residual income = NOPAT – Total capital charge

NOPAT = EBIT × (1 – Tax rate)

NOPAT = €700 million × (1 – 0.35) = €455 million

The total capital charge is as follows.

Equity charge = Total assets × Equity weighting × Cost of equity

= €4,000 million × 0.40 × 0.15

= €240 million

Debt charge = Total assets × Debt weighting × Pretax cost of debt × (1 – Tax rate)

= €4,000 million × 0.60 × 0.052(1 – 0.35)

= €81.1 million

Total capital charge = €240 million + €81.1 million = €321.1 million

Therefore, residual income = €455 million – €321.1 million = €133.9 million