Amigo Mobility, which manufactures battery-powered mobility scooters, has $675,000 to invest. The company is considering three different battery projects that will yield the following rates of return:

Deep cycle = 21%

Wet/flooded = 45%

Lithium ion = 28%

The initial investment required for each project is $175,000, $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 %.