Estimate an appropriate cost of capital benchmark for a long-term safe project based on the following data:

YTM on T-bills = 2.5% YTM on T-bonds = 5.7%

historical arithmetic equity premium over T-bills = 10.0% historical arithmetic equity premium over T-bonds = 7.5% historical geometric equity premium over T-bills = 7.8% historical geometric equity premium over T-bonds = 5.9%

Give your answer in percentage to the nearest 0.1 percentage point.