The weight of the ordinary shares used in the computation of the WACC is based on the number of shares in issue multiplied by the book value per share.

The firm's WACC will decrease as the corporate tax rate decreases.

When computing the WACC, the weight assigned to the preference shares is based on the coupon rate multiplied by the par value of the preference.

The WACC will remain constant unless a firm retires some of its debt.

The WACC should decrease as the firm's debt-equity ratio increases.