Retained earnings versus new common stock?? Using the data for a firm shown in the following? table, calculate the cost of retained earnings and the cost of new common stock using the? constant-growth valuation model.???

Current market price per share: $66.00

Dividend growth rate: 7?%

Projected dividend per share next year: $3.30

Underpricing per share: $2.50

Flotation cost per share:? ??$2.25

a. The cost of retained earnings is ? %? ?(Round to two decimal? places).