if a firm just paid a dividend equal to $4.00 a share, then for the WACC, in order to find the cost of equity, $4 should be

To find the cost of equity for a firm, you need to use a formula called the dividend discount model (DDM) or the Gordon growth model. The DDM formula is:

Cost of Equity = Dividend per Share / Price per Share

In this case, if a firm paid a dividend equal to $4.00 a share, you need to divide this dividend amount by the price per share to find the cost of equity.

However, the given information does not provide the price per share or any other details required to calculate the cost of equity accurately. Without knowing the current price per share or other inputs, it is not possible to determine the cost of equity using just the information that a $4.00 dividend was paid.

To calculate the cost of equity accurately, you would need additional information, such as the stock price, the expected growth rate of dividends, and the risk-free rate.