Answer: 2.5 meters
This value is exact without any rounding.
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Explanation:
The first task is to convert the mixed number 20⅚ into an improper fraction
I'll write 20⅚ as 20 & 5/6
The rule to use is a & b/c = (a*c + b)/c
So,
a & b/c = (a*c + b)/c
20 & 5/6 = (20*6+5)/6
20 & 5/6 = 125/6
This means the volume is exactly (125/6)pi cubic meters.
Plug this into the sphere volume formula and isolate the radius r like so
V = (4/3)*pi*r^3
(125/6)pi = (4/3)*pi*r^3
125/6 = (4/3)*r^3
(4/3)*r^3 = 125/6
4r^3 = 3*(125/6)
4r^3 = 125/2
r^3 = (125/2)*(1/4)
r^3 = 125/8
r = (125/8)^(1/3)
r = 5/2
r = 2.5
