RIVISITATO !!!
volume sfera = 4πr^3/3 = 4πd^3/(3*8) = π/6d^3 = 0,52360d^3
basic volume V = 0,52360*1^3 = 0,52360 dm^3
max volume Vma = 0,52360*1,06^3 = 0,62362 dm^3
min volume Vmi = 0,52360*0,94^3 = 0,43489 dm^3
massa base mb = 5,0 kg
massa min mmi= 4,6 kg
massa max mma= 5,4 kg
basic density ρ = mb/Vb = 5/0,52360 = 9,5493 kg/dm^3
max density ρma = mma/Vmi = 5,4/0,43489 = 12,417 kg/dm^3
min density ρmi = mmi/Vma = 4,6/0,62362 = 7,3763 kg/dm^3
density with absolute tolerance ρa:
ρa = ρ ± (ρma-ρmi)/2 = 9,5493±(12,417-7,3763)/2 = (9,5493±2,5204) kg/dm^3
density with relative tolerance ρr:
ρr = ρ ± ((ρma-ρmi)/(2*ρ)
ρr = 9,5493±(2,5204/9,5493) = 9,5493 kg/dm^3 ± 0,264
density with relative tolerance ρr in %:
ρr % = ρ ± 100*((ρma-ρmi)/(2*ρ)
ρr % = 9,5493±100*0,264 = 9,5493 kg/dm^3 ± 26,4%