36(3.14) = 4/3 x 3.14 x r^3
113.04 = 4.187(r^3)
113.04/4.187 = r^3
26.997 = r^3
3√26.997 = r
r = ~3
Check: 3^3(

)(4/3) = 27(3.14)(4/3) = 113.04
Keeping in mind that 29/6 is greater than 4, is actually 4 and 5/6, so the amount we'll "add" will be a negative one.
Your answer would be 5.10... Hope this helps :)
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She has 15 things on her to do list. Hope this helps!