Three metal strings (each a length of 70 cm) made of aluminum are attached to the ceiling, and a mass (68 kg) is hung on all three. How thick (what radius) should each string be in order to produce a E-major chord when they are “strummed?” The density of aluminum is 2.70 g/cm^3, and the three notes of a E-major chord are: 330 Hz, 415 Hz and 494 Hz.