Amigo Mobility, which manufactures battery-powered mobility scooters, has $660,000 to invest. The company is considering three different battery projects that will yield the following rates of return: Deep cycle-21% wet/flooded 49% : Lithium ion-28% The initial investment required for each project is $160,000, $100,000, and $400,000, respectively. If Amigo's invests in all three projects, what will be its overall rate of return? The rate of return is %